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How to calculate amount of days passed from one date to another in Android Studio with java? [duplicate]

I want a Java program that calculates days between two dates.
Type the first date (German notation; with whitespaces: "dd mm yyyy")
Type the second date.
The program should calculates the number of days between the two dates.
How can I include leap years and summertime?
My code:
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;
public class NewDateDifference {
public static void main(String[] args) {
System.out.print("Insert first date: ");
Scanner s = new Scanner(System.in);
String[] eingabe1 = new String[3];
while (s.hasNext()) {
int i = 0;
insert1[i] = s.next();
if (!s.hasNext()) {
s.close();
break;
}
i++;
}
System.out.print("Insert second date: ");
Scanner t = new Scanner(System.in);
String[] insert2 = new String[3];
while (t.hasNext()) {
int i = 0;
insert2[i] = t.next();
if (!t.hasNext()) {
t.close();
break;
}
i++;
}
Calendar cal = Calendar.getInstance();
cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert1[0]));
cal.set(Calendar.MONTH, Integer.parseInt(insert1[1]));
cal.set(Calendar.YEAR, Integer.parseInt(insert1[2]));
Date firstDate = cal.getTime();
cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert2[0]));
cal.set(Calendar.MONTH, Integer.parseInt(insert2[1]));
cal.set(Calendar.YEAR, Integer.parseInt(insert2[2]));
Date secondDate = cal.getTime();
long diff = secondDate.getTime() - firstDate.getTime();
System.out.println ("Days: " + diff / 1000 / 60 / 60 / 24);
}
}

UPDATE: The original answer from 2013 is now outdated because some of the classes have been replaced. The new way of doing this is using the new java.time classes.
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd MM yyyy");
String inputString1 = "23 01 1997";
String inputString2 = "27 04 1997";
try {
LocalDateTime date1 = LocalDate.parse(inputString1, dtf);
LocalDateTime date2 = LocalDate.parse(inputString2, dtf);
long daysBetween = Duration.between(date1, date2).toDays();
System.out.println ("Days: " + daysBetween);
} catch (ParseException e) {
e.printStackTrace();
}
Note that this solution will give the number of actual 24 hour-days, not the number of calendar days. For the latter, use
long daysBetween = ChronoUnit.DAYS.between(date1, date2)
Original answer (outdated as of Java 8)
You are making some conversions with your Strings that are not necessary. There is a SimpleDateFormat class for it - try this:
SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
String inputString1 = "23 01 1997";
String inputString2 = "27 04 1997";
try {
Date date1 = myFormat.parse(inputString1);
Date date2 = myFormat.parse(inputString2);
long diff = date2.getTime() - date1.getTime();
System.out.println ("Days: " + TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS));
} catch (ParseException e) {
e.printStackTrace();
}
EDIT: Since there have been some discussions regarding the correctness of this code: it does indeed take care of leap years. However, the TimeUnit.DAYS.convert function loses precision since milliseconds are converted to days (see the linked doc for more info). If this is a problem, diff can also be converted by hand:
float days = (diff / (1000*60*60*24));
Note that this is a float value, not necessarily an int.

Simplest way:
public static long getDifferenceDays(Date d1, Date d2) {
long diff = d2.getTime() - d1.getTime();
return TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS);
}

In Java 8, you could accomplish this by using LocalDate and DateTimeFormatter. From the Javadoc of LocalDate:
LocalDate is an immutable date-time object that represents a date,
often viewed as year-month-day.
And the pattern can be constructed using DateTimeFormatter. Here is the Javadoc, and the relevant pattern characters I used:
Symbol - Meaning - Presentation - Examples
y - year-of-era - year - 2004; 04
M/L - month-of-year - number/text - 7; 07; Jul;
July; J
d - day-of-month - number - 10
Here is the example:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
public class Java8DateExample {
public static void main(String[] args) throws IOException {
final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd MM yyyy");
final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
final String firstInput = reader.readLine();
final String secondInput = reader.readLine();
final LocalDate firstDate = LocalDate.parse(firstInput, formatter);
final LocalDate secondDate = LocalDate.parse(secondInput, formatter);
final long days = ChronoUnit.DAYS.between(firstDate, secondDate);
System.out.println("Days between: " + days);
}
}
Example input/output with more recent last:
23 01 1997
27 04 1997
Days between: 94
With more recent first:
27 04 1997
23 01 1997
Days between: -94
Well, you could do it as a method in a simpler way:
public static long betweenDates(Date firstDate, Date secondDate) throws IOException
{
return ChronoUnit.DAYS.between(firstDate.toInstant(), secondDate.toInstant());
}

Most / all answers caused issues for us when daylight savings time came around. Here's our working solution for all dates, without using JodaTime. It utilizes calendar objects:
public static int daysBetween(Calendar day1, Calendar day2){
Calendar dayOne = (Calendar) day1.clone(),
dayTwo = (Calendar) day2.clone();
if (dayOne.get(Calendar.YEAR) == dayTwo.get(Calendar.YEAR)) {
return Math.abs(dayOne.get(Calendar.DAY_OF_YEAR) - dayTwo.get(Calendar.DAY_OF_YEAR));
} else {
if (dayTwo.get(Calendar.YEAR) > dayOne.get(Calendar.YEAR)) {
//swap them
Calendar temp = dayOne;
dayOne = dayTwo;
dayTwo = temp;
}
int extraDays = 0;
int dayOneOriginalYearDays = dayOne.get(Calendar.DAY_OF_YEAR);
while (dayOne.get(Calendar.YEAR) > dayTwo.get(Calendar.YEAR)) {
dayOne.add(Calendar.YEAR, -1);
// getActualMaximum() important for leap years
extraDays += dayOne.getActualMaximum(Calendar.DAY_OF_YEAR);
}
return extraDays - dayTwo.get(Calendar.DAY_OF_YEAR) + dayOneOriginalYearDays ;
}
}

The best way, and it converts to a String as bonus ;)
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
//Dates to compare
String CurrentDate= "09/24/2015";
String FinalDate= "09/26/2015";
Date date1;
Date date2;
SimpleDateFormat dates = new SimpleDateFormat("MM/dd/yyyy");
//Setting dates
date1 = dates.parse(CurrentDate);
date2 = dates.parse(FinalDate);
//Comparing dates
long difference = Math.abs(date1.getTime() - date2.getTime());
long differenceDates = difference / (24 * 60 * 60 * 1000);
//Convert long to String
String dayDifference = Long.toString(differenceDates);
Log.e("HERE","HERE: " + dayDifference);
}
catch (Exception exception) {
Log.e("DIDN'T WORK", "exception " + exception);
}
}

Use:
public int getDifferenceDays(Date d1, Date d2) {
int daysdiff = 0;
long diff = d2.getTime() - d1.getTime();
long diffDays = diff / (24 * 60 * 60 * 1000) + 1;
daysdiff = (int) diffDays;
return daysdiff;
}

Java date libraries are notoriously broken. I would advise to use Joda Time. It will take care of leap year, time zone and so on for you.
Minimal working example:
import java.util.Scanner;
import org.joda.time.DateTime;
import org.joda.time.Days;
import org.joda.time.LocalDate;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
public class DateTestCase {
public static void main(String[] args) {
System.out.print("Insert first date: ");
Scanner s = new Scanner(System.in);
String firstdate = s.nextLine();
System.out.print("Insert second date: ");
String seconddate = s.nextLine();
// Formatter
DateTimeFormatter dateStringFormat = DateTimeFormat
.forPattern("dd MM yyyy");
DateTime firstTime = dateStringFormat.parseDateTime(firstdate);
DateTime secondTime = dateStringFormat.parseDateTime(seconddate);
int days = Days.daysBetween(new LocalDate(firstTime),
new LocalDate(secondTime)).getDays();
System.out.println("Days between the two dates " + days);
}
}

String dateStart = "01/14/2015 08:29:58";
String dateStop = "01/15/2015 11:31:48";
//HH converts hour in 24 hours format (0-23), day calculation
SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date d1 = null;
Date d2 = null;
d1 = format.parse(dateStart);
d2 = format.parse(dateStop);
//in milliseconds
long diff = d2.getTime() - d1.getTime();
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);
System.out.print(diffDays + " days, ");
System.out.print(diffHours + " hours, ");
System.out.print(diffMinutes + " minutes, ");
System.out.print(diffSeconds + " seconds.");

want to get just days(no times) you can use ChronoUnit
ChronoUnit.DAYS.between(date1.toLocalDate(), date2.toLocalDate());

We can make use of LocalDate and ChronoUnit java library, Below code is working fine.
Date should be in format yyyy-MM-dd.
import java.time.LocalDate;
import java.time.temporal.ChronoUnit;
import java.util.*;
class Solution {
public int daysBetweenDates(String date1, String date2) {
LocalDate dt1 = LocalDate.parse(date1);
LocalDate dt2= LocalDate.parse(date2);
long diffDays = ChronoUnit.DAYS.between(dt1, dt2);
return Math.abs((int)diffDays);
}
}

When I run your program, it doesn't even get me
to the point where I can enter the second date.
This is simpler and less error prone.
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Test001 {
public static void main(String[] args) throws Exception {
BufferedReader br = null;
br = new BufferedReader(new InputStreamReader(System.in));
SimpleDateFormat sdf = new SimpleDateFormat("dd MM yyyy");
System.out.println("Insert first date : ");
Date dt1 = sdf.parse(br.readLine().trim());
System.out.println("Insert second date : ");
Date dt2 = sdf.parse(br.readLine().trim());
long diff = dt2.getTime() - dt1.getTime();
System.out.println("Days: " + diff / 1000L / 60L / 60L / 24L);
if (br != null) {
br.close();
}
}
}

// date format, it will be like "2015-01-01"
private static final String DATE_FORMAT = "yyyy-MM-dd";
// convert a string to java.util.Date
public static Date convertStringToJavaDate(String date)
throws ParseException {
DateFormat dataFormat = new SimpleDateFormat(DATE_FORMAT);
return dataFormat.parse(date);
}
// plus days to a date
public static Date plusJavaDays(Date date, int days) {
// convert to jata-time
DateTime fromDate = new DateTime(date);
DateTime toDate = fromDate.plusDays(days);
// convert back to java.util.Date
return toDate.toDate();
}
// return a list of dates between the fromDate and toDate
public static List<Date> getDatesBetween(Date fromDate, Date toDate) {
List<Date> dates = new ArrayList<Date>(0);
Date date = fromDate;
while (date.before(toDate) || date.equals(toDate)) {
dates.add(date);
date = plusJavaDays(date, 1);
}
return dates;
}

The following works perfectly well for me:
public int daysBetween(LocalDate later, LocalDate before) {
SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
int daysBetween = 0;
try {
Date dateBefore = myFormat.parse(localDateToString(before));
Date dateAfter = myFormat.parse(localDateToString(later));
long difference = dateAfter.getTime() - dateBefore.getTime();
daysBetween = (int) (difference / (1000 * 60 * 60 * 24));
} catch (Exception e) {
e.printStackTrace();
}
return daysBetween;
}
public String localDateToString(LocalDate date) {
DateTimeFormatter myFormat = DateTimeFormatter.ofPattern("dd MM yyyy");
return date.format(myFormat).toString();
}

All the other answers had lots of scary things, here's my simple solution:
public int getDaysDiff(Date dateToCheck)
{
long diffMilliseconds = new Date().getTime() - dateToCheck.getTime();
double diffSeconds = diffMilliseconds / 1000;
double diffMinutes = diffSeconds / 60;
double diffHours = diffMinutes / 60;
double diffDays = diffHours / 24;
return (int) Math.round(diffDays);
}

public class TestCode {
public static void main(String[] args) {
String date1 = "23-04-2021";
String date2 = "24-05-2021";
System.out.println("NDays: " + nDays_Between_Dates(date1, date2));
}
public static int nDays_Between_Dates(String date1, String date2) {
int diffDays = 0;
try {
SimpleDateFormat dates = new SimpleDateFormat("dd-MM-yyyy");
Date startDate = dates.parse(date1);
Date endDate = dates.parse(date2);
long diff = endDate.getTime() - startDate.getTime();
diffDays = (int) (diff / (24 * 60 * 60 * 1000));
} catch (ParseException e) {
e.printStackTrace();
}
return Math.abs(diffDays);
}
}
Output: NDays: 31

public static String dateCalculation(String getTime, String dependTime) {
//Time A is getTime that need to calculate.
//Time B is static time that Time A depend on B Time and calculate the result.
Date date = new Date();
final SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd H:mm:ss");
Date dateObj = null;
Date checkDate = null;
try {
dateObj = sdf.parse(getTime);
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
String checkInDate = dateFormat.format(dateObj).toString();
Date defaultTime = null;
try {
defaultTime = dateFormat.parse(dependTime);
checkDate = dateFormat.parse(checkInDate);
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
try {
if (dateFormat.parse(dateFormat.format(date)).after(defaultTime)) {
long diff = checkDate.getTime() - defaultTime.getTime();
Log.e("Difference", "onBindViewHolder: Difference: " + dateObj + " : " + defaultTime + " : " + diff);
if (diff > 0) {
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000);
return "Late: " + diffHours + " Hour, " + diffMinutes + " Minutes, " + diffSeconds + " Sec";
} else {
return "0";
}
}
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
return "0";
}

How can i calculate the days between two user inputs that are to be determined once entered? [duplicate]

I want a Java program that calculates days between two dates.
Type the first date (German notation; with whitespaces: "dd mm yyyy")
Type the second date.
The program should calculates the number of days between the two dates.
How can I include leap years and summertime?
My code:
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;
public class NewDateDifference {
public static void main(String[] args) {
System.out.print("Insert first date: ");
Scanner s = new Scanner(System.in);
String[] eingabe1 = new String[3];
while (s.hasNext()) {
int i = 0;
insert1[i] = s.next();
if (!s.hasNext()) {
s.close();
break;
}
i++;
}
System.out.print("Insert second date: ");
Scanner t = new Scanner(System.in);
String[] insert2 = new String[3];
while (t.hasNext()) {
int i = 0;
insert2[i] = t.next();
if (!t.hasNext()) {
t.close();
break;
}
i++;
}
Calendar cal = Calendar.getInstance();
cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert1[0]));
cal.set(Calendar.MONTH, Integer.parseInt(insert1[1]));
cal.set(Calendar.YEAR, Integer.parseInt(insert1[2]));
Date firstDate = cal.getTime();
cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert2[0]));
cal.set(Calendar.MONTH, Integer.parseInt(insert2[1]));
cal.set(Calendar.YEAR, Integer.parseInt(insert2[2]));
Date secondDate = cal.getTime();
long diff = secondDate.getTime() - firstDate.getTime();
System.out.println ("Days: " + diff / 1000 / 60 / 60 / 24);
}
}

UPDATE: The original answer from 2013 is now outdated because some of the classes have been replaced. The new way of doing this is using the new java.time classes.
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd MM yyyy");
String inputString1 = "23 01 1997";
String inputString2 = "27 04 1997";
try {
LocalDateTime date1 = LocalDate.parse(inputString1, dtf);
LocalDateTime date2 = LocalDate.parse(inputString2, dtf);
long daysBetween = Duration.between(date1, date2).toDays();
System.out.println ("Days: " + daysBetween);
} catch (ParseException e) {
e.printStackTrace();
}
Note that this solution will give the number of actual 24 hour-days, not the number of calendar days. For the latter, use
long daysBetween = ChronoUnit.DAYS.between(date1, date2)
Original answer (outdated as of Java 8)
You are making some conversions with your Strings that are not necessary. There is a SimpleDateFormat class for it - try this:
SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
String inputString1 = "23 01 1997";
String inputString2 = "27 04 1997";
try {
Date date1 = myFormat.parse(inputString1);
Date date2 = myFormat.parse(inputString2);
long diff = date2.getTime() - date1.getTime();
System.out.println ("Days: " + TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS));
} catch (ParseException e) {
e.printStackTrace();
}
EDIT: Since there have been some discussions regarding the correctness of this code: it does indeed take care of leap years. However, the TimeUnit.DAYS.convert function loses precision since milliseconds are converted to days (see the linked doc for more info). If this is a problem, diff can also be converted by hand:
float days = (diff / (1000*60*60*24));
Note that this is a float value, not necessarily an int.

Simplest way:
public static long getDifferenceDays(Date d1, Date d2) {
long diff = d2.getTime() - d1.getTime();
return TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS);
}

In Java 8, you could accomplish this by using LocalDate and DateTimeFormatter. From the Javadoc of LocalDate:
LocalDate is an immutable date-time object that represents a date,
often viewed as year-month-day.
And the pattern can be constructed using DateTimeFormatter. Here is the Javadoc, and the relevant pattern characters I used:
Symbol - Meaning - Presentation - Examples
y - year-of-era - year - 2004; 04
M/L - month-of-year - number/text - 7; 07; Jul;
July; J
d - day-of-month - number - 10
Here is the example:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
public class Java8DateExample {
public static void main(String[] args) throws IOException {
final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd MM yyyy");
final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
final String firstInput = reader.readLine();
final String secondInput = reader.readLine();
final LocalDate firstDate = LocalDate.parse(firstInput, formatter);
final LocalDate secondDate = LocalDate.parse(secondInput, formatter);
final long days = ChronoUnit.DAYS.between(firstDate, secondDate);
System.out.println("Days between: " + days);
}
}
Example input/output with more recent last:
23 01 1997
27 04 1997
Days between: 94
With more recent first:
27 04 1997
23 01 1997
Days between: -94
Well, you could do it as a method in a simpler way:
public static long betweenDates(Date firstDate, Date secondDate) throws IOException
{
return ChronoUnit.DAYS.between(firstDate.toInstant(), secondDate.toInstant());
}

Most / all answers caused issues for us when daylight savings time came around. Here's our working solution for all dates, without using JodaTime. It utilizes calendar objects:
public static int daysBetween(Calendar day1, Calendar day2){
Calendar dayOne = (Calendar) day1.clone(),
dayTwo = (Calendar) day2.clone();
if (dayOne.get(Calendar.YEAR) == dayTwo.get(Calendar.YEAR)) {
return Math.abs(dayOne.get(Calendar.DAY_OF_YEAR) - dayTwo.get(Calendar.DAY_OF_YEAR));
} else {
if (dayTwo.get(Calendar.YEAR) > dayOne.get(Calendar.YEAR)) {
//swap them
Calendar temp = dayOne;
dayOne = dayTwo;
dayTwo = temp;
}
int extraDays = 0;
int dayOneOriginalYearDays = dayOne.get(Calendar.DAY_OF_YEAR);
while (dayOne.get(Calendar.YEAR) > dayTwo.get(Calendar.YEAR)) {
dayOne.add(Calendar.YEAR, -1);
// getActualMaximum() important for leap years
extraDays += dayOne.getActualMaximum(Calendar.DAY_OF_YEAR);
}
return extraDays - dayTwo.get(Calendar.DAY_OF_YEAR) + dayOneOriginalYearDays ;
}
}

The best way, and it converts to a String as bonus ;)
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
//Dates to compare
String CurrentDate= "09/24/2015";
String FinalDate= "09/26/2015";
Date date1;
Date date2;
SimpleDateFormat dates = new SimpleDateFormat("MM/dd/yyyy");
//Setting dates
date1 = dates.parse(CurrentDate);
date2 = dates.parse(FinalDate);
//Comparing dates
long difference = Math.abs(date1.getTime() - date2.getTime());
long differenceDates = difference / (24 * 60 * 60 * 1000);
//Convert long to String
String dayDifference = Long.toString(differenceDates);
Log.e("HERE","HERE: " + dayDifference);
}
catch (Exception exception) {
Log.e("DIDN'T WORK", "exception " + exception);
}
}

Use:
public int getDifferenceDays(Date d1, Date d2) {
int daysdiff = 0;
long diff = d2.getTime() - d1.getTime();
long diffDays = diff / (24 * 60 * 60 * 1000) + 1;
daysdiff = (int) diffDays;
return daysdiff;
}

Java date libraries are notoriously broken. I would advise to use Joda Time. It will take care of leap year, time zone and so on for you.
Minimal working example:
import java.util.Scanner;
import org.joda.time.DateTime;
import org.joda.time.Days;
import org.joda.time.LocalDate;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
public class DateTestCase {
public static void main(String[] args) {
System.out.print("Insert first date: ");
Scanner s = new Scanner(System.in);
String firstdate = s.nextLine();
System.out.print("Insert second date: ");
String seconddate = s.nextLine();
// Formatter
DateTimeFormatter dateStringFormat = DateTimeFormat
.forPattern("dd MM yyyy");
DateTime firstTime = dateStringFormat.parseDateTime(firstdate);
DateTime secondTime = dateStringFormat.parseDateTime(seconddate);
int days = Days.daysBetween(new LocalDate(firstTime),
new LocalDate(secondTime)).getDays();
System.out.println("Days between the two dates " + days);
}
}

String dateStart = "01/14/2015 08:29:58";
String dateStop = "01/15/2015 11:31:48";
//HH converts hour in 24 hours format (0-23), day calculation
SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date d1 = null;
Date d2 = null;
d1 = format.parse(dateStart);
d2 = format.parse(dateStop);
//in milliseconds
long diff = d2.getTime() - d1.getTime();
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);
System.out.print(diffDays + " days, ");
System.out.print(diffHours + " hours, ");
System.out.print(diffMinutes + " minutes, ");
System.out.print(diffSeconds + " seconds.");

want to get just days(no times) you can use ChronoUnit
ChronoUnit.DAYS.between(date1.toLocalDate(), date2.toLocalDate());

We can make use of LocalDate and ChronoUnit java library, Below code is working fine.
Date should be in format yyyy-MM-dd.
import java.time.LocalDate;
import java.time.temporal.ChronoUnit;
import java.util.*;
class Solution {
public int daysBetweenDates(String date1, String date2) {
LocalDate dt1 = LocalDate.parse(date1);
LocalDate dt2= LocalDate.parse(date2);
long diffDays = ChronoUnit.DAYS.between(dt1, dt2);
return Math.abs((int)diffDays);
}
}

When I run your program, it doesn't even get me
to the point where I can enter the second date.
This is simpler and less error prone.
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Test001 {
public static void main(String[] args) throws Exception {
BufferedReader br = null;
br = new BufferedReader(new InputStreamReader(System.in));
SimpleDateFormat sdf = new SimpleDateFormat("dd MM yyyy");
System.out.println("Insert first date : ");
Date dt1 = sdf.parse(br.readLine().trim());
System.out.println("Insert second date : ");
Date dt2 = sdf.parse(br.readLine().trim());
long diff = dt2.getTime() - dt1.getTime();
System.out.println("Days: " + diff / 1000L / 60L / 60L / 24L);
if (br != null) {
br.close();
}
}
}

// date format, it will be like "2015-01-01"
private static final String DATE_FORMAT = "yyyy-MM-dd";
// convert a string to java.util.Date
public static Date convertStringToJavaDate(String date)
throws ParseException {
DateFormat dataFormat = new SimpleDateFormat(DATE_FORMAT);
return dataFormat.parse(date);
}
// plus days to a date
public static Date plusJavaDays(Date date, int days) {
// convert to jata-time
DateTime fromDate = new DateTime(date);
DateTime toDate = fromDate.plusDays(days);
// convert back to java.util.Date
return toDate.toDate();
}
// return a list of dates between the fromDate and toDate
public static List<Date> getDatesBetween(Date fromDate, Date toDate) {
List<Date> dates = new ArrayList<Date>(0);
Date date = fromDate;
while (date.before(toDate) || date.equals(toDate)) {
dates.add(date);
date = plusJavaDays(date, 1);
}
return dates;
}

The following works perfectly well for me:
public int daysBetween(LocalDate later, LocalDate before) {
SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
int daysBetween = 0;
try {
Date dateBefore = myFormat.parse(localDateToString(before));
Date dateAfter = myFormat.parse(localDateToString(later));
long difference = dateAfter.getTime() - dateBefore.getTime();
daysBetween = (int) (difference / (1000 * 60 * 60 * 24));
} catch (Exception e) {
e.printStackTrace();
}
return daysBetween;
}
public String localDateToString(LocalDate date) {
DateTimeFormatter myFormat = DateTimeFormatter.ofPattern("dd MM yyyy");
return date.format(myFormat).toString();
}

All the other answers had lots of scary things, here's my simple solution:
public int getDaysDiff(Date dateToCheck)
{
long diffMilliseconds = new Date().getTime() - dateToCheck.getTime();
double diffSeconds = diffMilliseconds / 1000;
double diffMinutes = diffSeconds / 60;
double diffHours = diffMinutes / 60;
double diffDays = diffHours / 24;
return (int) Math.round(diffDays);
}

public class TestCode {
public static void main(String[] args) {
String date1 = "23-04-2021";
String date2 = "24-05-2021";
System.out.println("NDays: " + nDays_Between_Dates(date1, date2));
}
public static int nDays_Between_Dates(String date1, String date2) {
int diffDays = 0;
try {
SimpleDateFormat dates = new SimpleDateFormat("dd-MM-yyyy");
Date startDate = dates.parse(date1);
Date endDate = dates.parse(date2);
long diff = endDate.getTime() - startDate.getTime();
diffDays = (int) (diff / (24 * 60 * 60 * 1000));
} catch (ParseException e) {
e.printStackTrace();
}
return Math.abs(diffDays);
}
}
Output: NDays: 31

public static String dateCalculation(String getTime, String dependTime) {
//Time A is getTime that need to calculate.
//Time B is static time that Time A depend on B Time and calculate the result.
Date date = new Date();
final SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd H:mm:ss");
Date dateObj = null;
Date checkDate = null;
try {
dateObj = sdf.parse(getTime);
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
String checkInDate = dateFormat.format(dateObj).toString();
Date defaultTime = null;
try {
defaultTime = dateFormat.parse(dependTime);
checkDate = dateFormat.parse(checkInDate);
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
try {
if (dateFormat.parse(dateFormat.format(date)).after(defaultTime)) {
long diff = checkDate.getTime() - defaultTime.getTime();
Log.e("Difference", "onBindViewHolder: Difference: " + dateObj + " : " + defaultTime + " : " + diff);
if (diff > 0) {
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000);
return "Late: " + diffHours + " Hour, " + diffMinutes + " Minutes, " + diffSeconds + " Sec";
} else {
return "0";
}
}
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
return "0";
}

How to get Time ago in android? [duplicate]

I have two date like:
String date_1="yyyyMMddHHmmss";
String date_2="yyyyMMddHHmmss";
I want to print the difference like:
2d 3h 45m
How can I do that? Thanks!

DateTimeUtils obj = new DateTimeUtils();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/M/yyyy hh:mm:ss");
try {
Date date1 = simpleDateFormat.parse("10/10/2013 11:30:10");
Date date2 = simpleDateFormat.parse("13/10/2013 20:35:55");
obj.printDifference(date1, date2);
} catch (ParseException e) {
e.printStackTrace();
}
//1 minute = 60 seconds
//1 hour = 60 x 60 = 3600
//1 day = 3600 x 24 = 86400
public void printDifference(Date startDate, Date endDate) {
//milliseconds
long different = endDate.getTime() - startDate.getTime();
System.out.println("startDate : " + startDate);
System.out.println("endDate : "+ endDate);
System.out.println("different : " + different);
long secondsInMilli = 1000;
long minutesInMilli = secondsInMilli * 60;
long hoursInMilli = minutesInMilli * 60;
long daysInMilli = hoursInMilli * 24;
long elapsedDays = different / daysInMilli;
different = different % daysInMilli;
long elapsedHours = different / hoursInMilli;
different = different % hoursInMilli;
long elapsedMinutes = different / minutesInMilli;
different = different % minutesInMilli;
long elapsedSeconds = different / secondsInMilli;
System.out.printf(
"%d days, %d hours, %d minutes, %d seconds%n",
elapsedDays, elapsedHours, elapsedMinutes, elapsedSeconds);
}
out put is :
startDate : Thu Oct 10 11:30:10 SGT 2013
endDate : Sun Oct 13 20:35:55 SGT 2013
different : 291945000
3 days, 9 hours, 5 minutes, 45 seconds

Date userDob = new SimpleDateFormat("yyyy-MM-dd").parse(dob);
Date today = new Date();
long diff = today.getTime() - userDob.getTime();
int numOfDays = (int) (diff / (1000 * 60 * 60 * 24));
int hours = (int) (diff / (1000 * 60 * 60));
int minutes = (int) (diff / (1000 * 60));
int seconds = (int) (diff / (1000));

Short & Sweet:
/**
* Get a diff between two dates
*
* #param oldDate the old date
* #param newDate the new date
* #return the diff value, in the days
*/
public static long getDateDiff(SimpleDateFormat format, String oldDate, String newDate) {
try {
return TimeUnit.DAYS.convert(format.parse(newDate).getTime() - format.parse(oldDate).getTime(), TimeUnit.MILLISECONDS);
} catch (Exception e) {
e.printStackTrace();
return 0;
}
}
Usage:
int dateDifference = (int) getDateDiff(new SimpleDateFormat("dd/MM/yyyy"), "29/05/2017", "31/05/2017");
System.out.println("dateDifference: " + dateDifference);
Output:
dateDifference: 2
Kotlin Version:
#ExperimentalTime
fun getDateDiff(format: SimpleDateFormat, oldDate: String, newDate: String): Long {
return try {
DurationUnit.DAYS.convert(
format.parse(newDate).time - format.parse(oldDate).time,
DurationUnit.MILLISECONDS
)
} catch (e: Exception) {
e.printStackTrace()
0
}
}

This works and convert to String as a Bonus ;)
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
//Dates to compare
String CurrentDate= "09/24/2015";
String FinalDate= "09/26/2015";
Date date1;
Date date2;
SimpleDateFormat dates = new SimpleDateFormat("MM/dd/yyyy");
//Setting dates
date1 = dates.parse(CurrentDate);
date2 = dates.parse(FinalDate);
//Comparing dates
long difference = Math.abs(date1.getTime() - date2.getTime());
long differenceDates = difference / (24 * 60 * 60 * 1000);
//Convert long to String
String dayDifference = Long.toString(differenceDates);
Log.e("HERE","HERE: " + dayDifference);
} catch (Exception exception) {
Log.e("DIDN'T WORK", "exception " + exception);
}
}

It will give you difference in months
long milliSeconds1 = calendar1.getTimeInMillis();
long milliSeconds2 = calendar2.getTimeInMillis();
long periodSeconds = (milliSeconds2 - milliSeconds1) / 1000;
long elapsedDays = periodSeconds / 60 / 60 / 24;
System.out.println(String.format("%d months", elapsedDays/30));

Here is the modern answer. It’s good for anyone who either uses Java 8 or later (which doesn’t go for most Android phones yet) or is happy with an external library.
String date1 = "20170717141000";
String date2 = "20170719175500";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");
Duration diff = Duration.between(LocalDateTime.parse(date1, formatter),
LocalDateTime.parse(date2, formatter));
if (diff.isZero()) {
System.out.println("0m");
} else {
long days = diff.toDays();
if (days != 0) {
System.out.print("" + days + "d ");
diff = diff.minusDays(days);
}
long hours = diff.toHours();
if (hours != 0) {
System.out.print("" + hours + "h ");
diff = diff.minusHours(hours);
}
long minutes = diff.toMinutes();
if (minutes != 0) {
System.out.print("" + minutes + "m ");
diff = diff.minusMinutes(minutes);
}
long seconds = diff.getSeconds();
if (seconds != 0) {
System.out.print("" + seconds + "s ");
}
System.out.println();
}
This prints
2d 3h 45m
In my own opinion the advantage is not so much that it is shorter (it’s not much), but leaving the calculations to an standard library is less errorprone and gives you clearer code. These are great advantages. The reader is not burdened with recognizing constants like 24, 60 and 1000 and verifying that they are used correctly.
I am using the modern Java date & time API (described in JSR-310 and also known under this name). To use this on Android under API level 26, get the ThreeTenABP, see this question: How to use ThreeTenABP in Android Project. To use it with other Java 6 or 7, get ThreeTen Backport. With Java 8 and later it is built-in.
With Java 9 it will be still a bit easier since the Duration class is extended with methods to give you the days part, hours part, minutes part and seconds part separately so you don’t need the subtractions. See an example in my answer here.

I use this:
send start and end date in millisecond
public int GetDifference(long start,long end){
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(start);
int hour = cal.get(Calendar.HOUR_OF_DAY);
int min = cal.get(Calendar.MINUTE);
long t=(23-hour)*3600000+(59-min)*60000;
t=start+t;
int diff=0;
if(end>t){
diff=(int)((end-t)/ TimeUnit.DAYS.toMillis(1))+1;
}
return diff;
}

You can calculate the difference in time in miliseconds using this method and get the outputs in seconds, minutes, hours, days, months and years.
You can download class from here: DateTimeDifference GitHub Link
Simple to use
long currentTime = System.currentTimeMillis();
long previousTime = (System.currentTimeMillis() - 864000000); //10 days ago
Log.d("DateTime: ", "Difference With Second: " + AppUtility.DateTimeDifference(currentTime, previousTime, AppUtility.TimeDifference.SECOND));
Log.d("DateTime: ", "Difference With Minute: " + AppUtility.DateTimeDifference(currentTime, previousTime, AppUtility.TimeDifference.MINUTE));
You can compare the example below
if(AppUtility.DateTimeDifference(currentTime, previousTime, AppUtility.TimeDifference.MINUTE) > 100){
Log.d("DateTime: ", "There are more than 100 minutes difference between two dates.");
}else{
Log.d("DateTime: ", "There are no more than 100 minutes difference between two dates.");
}

Try this out.
int day = 0;
int hh = 0;
int mm = 0;
try {
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy 'at' hh:mm aa");
Date oldDate = dateFormat.parse(oldTime);
Date cDate = new Date();
Long timeDiff = cDate.getTime() - oldDate.getTime();
day = (int) TimeUnit.MILLISECONDS.toDays(timeDiff);
hh = (int) (TimeUnit.MILLISECONDS.toHours(timeDiff) - TimeUnit.DAYS.toHours(day));
mm = (int) (TimeUnit.MILLISECONDS.toMinutes(timeDiff) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(timeDiff)));
} catch (ParseException e) {
e.printStackTrace();
}
if (mm <= 60 && hh!= 0) {
if (hh <= 60 && day != 0) {
return day + " DAYS AGO";
} else {
return hh + " HOUR AGO";
}
} else {
return mm + " MIN AGO";
}

DateTime start = new DateTime(2013, 10, 20, 5, 0, 0, Locale);
DateTime end = new DateTime(2013, 10, 21, 13, 0, 0, Locale);
Days.daysBetween(start.toLocalDate(), end.toLocalDate()).getDays()
it returns how many days between given two dates, where DateTime is from joda library

I arranged a little. This works great.
#SuppressLint("SimpleDateFormat") SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd MM yyyy");
Date date = new Date();
String dateOfDay = simpleDateFormat.format(date);
String timeofday = android.text.format.DateFormat.format("HH:mm:ss", new Date().getTime()).toString();
#SuppressLint("SimpleDateFormat") SimpleDateFormat dateFormat = new SimpleDateFormat("dd MM yyyy hh:mm:ss");
try {
Date date1 = dateFormat.parse(06 09 2018 + " " + 10:12:56);
Date date2 = dateFormat.parse(dateOfDay + " " + timeofday);
printDifference(date1, date2);
} catch (ParseException e) {
e.printStackTrace();
}
#SuppressLint("SetTextI18n")
private void printDifference(Date startDate, Date endDate) {
//milliseconds
long different = endDate.getTime() - startDate.getTime();
long secondsInMilli = 1000;
long minutesInMilli = secondsInMilli * 60;
long hoursInMilli = minutesInMilli * 60;
long daysInMilli = hoursInMilli * 24;
long elapsedDays = different / daysInMilli;
different = different % daysInMilli;
long elapsedHours = different / hoursInMilli;
different = different % hoursInMilli;
long elapsedMinutes = different / minutesInMilli;
different = different % minutesInMilli;
long elapsedSeconds = different / secondsInMilli;
Toast.makeText(context, elapsedDays + " " + elapsedHours + " " + elapsedMinutes + " " + elapsedSeconds, Toast.LENGTH_SHORT).show();
}

Here's the simple solution:
fun printDaysBetweenTwoDates(): Int {
val dateFormat = SimpleDateFormat("dd-MM-yyyy", Locale.ENGLISH)
val endDateInMilliSeconds = dateFormat.parse("26-02-2022")?.time ?: 0
val startDateInMilliSeconds = dateFormat.parse("18-02-2022")?.time ?: 0
return getNumberOfDaysBetweenDates(startDateInMilliSeconds, endDateInMilliSeconds)
}
private fun getNumberOfDaysBetweenDates(
startDateInMilliSeconds: Long,
endDateInMilliSeconds: Long
): Int {
val difference = (endDateInMilliSeconds - startDateInMilliSeconds) / (1000 * 60 * 60 * 24).toDouble()
val noOfDays = Math.ceil(difference)
return (noOfDays).toInt()
}

When you use Date() to calculate the difference in hours is necessary configure the SimpleDateFormat() in UTC otherwise you get one hour error due to Daylight SavingTime.

You can generalize this into a function that lets you choose the output format
private String substractDates(Date date1, Date date2, SimpleDateFormat format) {
long restDatesinMillis = date1.getTime()-date2.getTime();
Date restdate = new Date(restDatesinMillis);
return format.format(restdate);
}
Now is a simple function call like this, difference in hours, minutes and seconds:
SimpleDateFormat formater = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try {
Date date1 = formater.parse(dateEnd);
Date date2 = formater.parse(dateInit);
String result = substractDates(date1, date2, new SimpleDateFormat("HH:mm:ss"));
txtTime.setText(result);
} catch (ParseException e) {
e.printStackTrace();
}

How to subtract time and date [duplicate]

I want a Java program that calculates days between two dates.
Type the first date (German notation; with whitespaces: "dd mm yyyy")
Type the second date.
The program should calculates the number of days between the two dates.
How can I include leap years and summertime?
My code:
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;
public class NewDateDifference {
public static void main(String[] args) {
System.out.print("Insert first date: ");
Scanner s = new Scanner(System.in);
String[] eingabe1 = new String[3];
while (s.hasNext()) {
int i = 0;
insert1[i] = s.next();
if (!s.hasNext()) {
s.close();
break;
}
i++;
}
System.out.print("Insert second date: ");
Scanner t = new Scanner(System.in);
String[] insert2 = new String[3];
while (t.hasNext()) {
int i = 0;
insert2[i] = t.next();
if (!t.hasNext()) {
t.close();
break;
}
i++;
}
Calendar cal = Calendar.getInstance();
cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert1[0]));
cal.set(Calendar.MONTH, Integer.parseInt(insert1[1]));
cal.set(Calendar.YEAR, Integer.parseInt(insert1[2]));
Date firstDate = cal.getTime();
cal.set(Calendar.DAY_OF_MONTH, Integer.parseInt(insert2[0]));
cal.set(Calendar.MONTH, Integer.parseInt(insert2[1]));
cal.set(Calendar.YEAR, Integer.parseInt(insert2[2]));
Date secondDate = cal.getTime();
long diff = secondDate.getTime() - firstDate.getTime();
System.out.println ("Days: " + diff / 1000 / 60 / 60 / 24);
}
}

UPDATE: The original answer from 2013 is now outdated because some of the classes have been replaced. The new way of doing this is using the new java.time classes.
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd MM yyyy");
String inputString1 = "23 01 1997";
String inputString2 = "27 04 1997";
try {
LocalDateTime date1 = LocalDate.parse(inputString1, dtf);
LocalDateTime date2 = LocalDate.parse(inputString2, dtf);
long daysBetween = Duration.between(date1, date2).toDays();
System.out.println ("Days: " + daysBetween);
} catch (ParseException e) {
e.printStackTrace();
}
Note that this solution will give the number of actual 24 hour-days, not the number of calendar days. For the latter, use
long daysBetween = ChronoUnit.DAYS.between(date1, date2)
Original answer (outdated as of Java 8)
You are making some conversions with your Strings that are not necessary. There is a SimpleDateFormat class for it - try this:
SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
String inputString1 = "23 01 1997";
String inputString2 = "27 04 1997";
try {
Date date1 = myFormat.parse(inputString1);
Date date2 = myFormat.parse(inputString2);
long diff = date2.getTime() - date1.getTime();
System.out.println ("Days: " + TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS));
} catch (ParseException e) {
e.printStackTrace();
}
EDIT: Since there have been some discussions regarding the correctness of this code: it does indeed take care of leap years. However, the TimeUnit.DAYS.convert function loses precision since milliseconds are converted to days (see the linked doc for more info). If this is a problem, diff can also be converted by hand:
float days = (diff / (1000*60*60*24));
Note that this is a float value, not necessarily an int.

Simplest way:
public static long getDifferenceDays(Date d1, Date d2) {
long diff = d2.getTime() - d1.getTime();
return TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS);
}

In Java 8, you could accomplish this by using LocalDate and DateTimeFormatter. From the Javadoc of LocalDate:
LocalDate is an immutable date-time object that represents a date,
often viewed as year-month-day.
And the pattern can be constructed using DateTimeFormatter. Here is the Javadoc, and the relevant pattern characters I used:
Symbol - Meaning - Presentation - Examples
y - year-of-era - year - 2004; 04
M/L - month-of-year - number/text - 7; 07; Jul;
July; J
d - day-of-month - number - 10
Here is the example:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
public class Java8DateExample {
public static void main(String[] args) throws IOException {
final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd MM yyyy");
final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
final String firstInput = reader.readLine();
final String secondInput = reader.readLine();
final LocalDate firstDate = LocalDate.parse(firstInput, formatter);
final LocalDate secondDate = LocalDate.parse(secondInput, formatter);
final long days = ChronoUnit.DAYS.between(firstDate, secondDate);
System.out.println("Days between: " + days);
}
}
Example input/output with more recent last:
23 01 1997
27 04 1997
Days between: 94
With more recent first:
27 04 1997
23 01 1997
Days between: -94
Well, you could do it as a method in a simpler way:
public static long betweenDates(Date firstDate, Date secondDate) throws IOException
{
return ChronoUnit.DAYS.between(firstDate.toInstant(), secondDate.toInstant());
}

Most / all answers caused issues for us when daylight savings time came around. Here's our working solution for all dates, without using JodaTime. It utilizes calendar objects:
public static int daysBetween(Calendar day1, Calendar day2){
Calendar dayOne = (Calendar) day1.clone(),
dayTwo = (Calendar) day2.clone();
if (dayOne.get(Calendar.YEAR) == dayTwo.get(Calendar.YEAR)) {
return Math.abs(dayOne.get(Calendar.DAY_OF_YEAR) - dayTwo.get(Calendar.DAY_OF_YEAR));
} else {
if (dayTwo.get(Calendar.YEAR) > dayOne.get(Calendar.YEAR)) {
//swap them
Calendar temp = dayOne;
dayOne = dayTwo;
dayTwo = temp;
}
int extraDays = 0;
int dayOneOriginalYearDays = dayOne.get(Calendar.DAY_OF_YEAR);
while (dayOne.get(Calendar.YEAR) > dayTwo.get(Calendar.YEAR)) {
dayOne.add(Calendar.YEAR, -1);
// getActualMaximum() important for leap years
extraDays += dayOne.getActualMaximum(Calendar.DAY_OF_YEAR);
}
return extraDays - dayTwo.get(Calendar.DAY_OF_YEAR) + dayOneOriginalYearDays ;
}
}

The best way, and it converts to a String as bonus ;)
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
//Dates to compare
String CurrentDate= "09/24/2015";
String FinalDate= "09/26/2015";
Date date1;
Date date2;
SimpleDateFormat dates = new SimpleDateFormat("MM/dd/yyyy");
//Setting dates
date1 = dates.parse(CurrentDate);
date2 = dates.parse(FinalDate);
//Comparing dates
long difference = Math.abs(date1.getTime() - date2.getTime());
long differenceDates = difference / (24 * 60 * 60 * 1000);
//Convert long to String
String dayDifference = Long.toString(differenceDates);
Log.e("HERE","HERE: " + dayDifference);
}
catch (Exception exception) {
Log.e("DIDN'T WORK", "exception " + exception);
}
}

Use:
public int getDifferenceDays(Date d1, Date d2) {
int daysdiff = 0;
long diff = d2.getTime() - d1.getTime();
long diffDays = diff / (24 * 60 * 60 * 1000) + 1;
daysdiff = (int) diffDays;
return daysdiff;
}

Java date libraries are notoriously broken. I would advise to use Joda Time. It will take care of leap year, time zone and so on for you.
Minimal working example:
import java.util.Scanner;
import org.joda.time.DateTime;
import org.joda.time.Days;
import org.joda.time.LocalDate;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
public class DateTestCase {
public static void main(String[] args) {
System.out.print("Insert first date: ");
Scanner s = new Scanner(System.in);
String firstdate = s.nextLine();
System.out.print("Insert second date: ");
String seconddate = s.nextLine();
// Formatter
DateTimeFormatter dateStringFormat = DateTimeFormat
.forPattern("dd MM yyyy");
DateTime firstTime = dateStringFormat.parseDateTime(firstdate);
DateTime secondTime = dateStringFormat.parseDateTime(seconddate);
int days = Days.daysBetween(new LocalDate(firstTime),
new LocalDate(secondTime)).getDays();
System.out.println("Days between the two dates " + days);
}
}

String dateStart = "01/14/2015 08:29:58";
String dateStop = "01/15/2015 11:31:48";
//HH converts hour in 24 hours format (0-23), day calculation
SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date d1 = null;
Date d2 = null;
d1 = format.parse(dateStart);
d2 = format.parse(dateStop);
//in milliseconds
long diff = d2.getTime() - d1.getTime();
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);
System.out.print(diffDays + " days, ");
System.out.print(diffHours + " hours, ");
System.out.print(diffMinutes + " minutes, ");
System.out.print(diffSeconds + " seconds.");

want to get just days(no times) you can use ChronoUnit
ChronoUnit.DAYS.between(date1.toLocalDate(), date2.toLocalDate());

We can make use of LocalDate and ChronoUnit java library, Below code is working fine.
Date should be in format yyyy-MM-dd.
import java.time.LocalDate;
import java.time.temporal.ChronoUnit;
import java.util.*;
class Solution {
public int daysBetweenDates(String date1, String date2) {
LocalDate dt1 = LocalDate.parse(date1);
LocalDate dt2= LocalDate.parse(date2);
long diffDays = ChronoUnit.DAYS.between(dt1, dt2);
return Math.abs((int)diffDays);
}
}

When I run your program, it doesn't even get me
to the point where I can enter the second date.
This is simpler and less error prone.
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.text.SimpleDateFormat;
import java.util.Date;
public class Test001 {
public static void main(String[] args) throws Exception {
BufferedReader br = null;
br = new BufferedReader(new InputStreamReader(System.in));
SimpleDateFormat sdf = new SimpleDateFormat("dd MM yyyy");
System.out.println("Insert first date : ");
Date dt1 = sdf.parse(br.readLine().trim());
System.out.println("Insert second date : ");
Date dt2 = sdf.parse(br.readLine().trim());
long diff = dt2.getTime() - dt1.getTime();
System.out.println("Days: " + diff / 1000L / 60L / 60L / 24L);
if (br != null) {
br.close();
}
}
}

// date format, it will be like "2015-01-01"
private static final String DATE_FORMAT = "yyyy-MM-dd";
// convert a string to java.util.Date
public static Date convertStringToJavaDate(String date)
throws ParseException {
DateFormat dataFormat = new SimpleDateFormat(DATE_FORMAT);
return dataFormat.parse(date);
}
// plus days to a date
public static Date plusJavaDays(Date date, int days) {
// convert to jata-time
DateTime fromDate = new DateTime(date);
DateTime toDate = fromDate.plusDays(days);
// convert back to java.util.Date
return toDate.toDate();
}
// return a list of dates between the fromDate and toDate
public static List<Date> getDatesBetween(Date fromDate, Date toDate) {
List<Date> dates = new ArrayList<Date>(0);
Date date = fromDate;
while (date.before(toDate) || date.equals(toDate)) {
dates.add(date);
date = plusJavaDays(date, 1);
}
return dates;
}

The following works perfectly well for me:
public int daysBetween(LocalDate later, LocalDate before) {
SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
int daysBetween = 0;
try {
Date dateBefore = myFormat.parse(localDateToString(before));
Date dateAfter = myFormat.parse(localDateToString(later));
long difference = dateAfter.getTime() - dateBefore.getTime();
daysBetween = (int) (difference / (1000 * 60 * 60 * 24));
} catch (Exception e) {
e.printStackTrace();
}
return daysBetween;
}
public String localDateToString(LocalDate date) {
DateTimeFormatter myFormat = DateTimeFormatter.ofPattern("dd MM yyyy");
return date.format(myFormat).toString();
}

All the other answers had lots of scary things, here's my simple solution:
public int getDaysDiff(Date dateToCheck)
{
long diffMilliseconds = new Date().getTime() - dateToCheck.getTime();
double diffSeconds = diffMilliseconds / 1000;
double diffMinutes = diffSeconds / 60;
double diffHours = diffMinutes / 60;
double diffDays = diffHours / 24;
return (int) Math.round(diffDays);
}

public class TestCode {
public static void main(String[] args) {
String date1 = "23-04-2021";
String date2 = "24-05-2021";
System.out.println("NDays: " + nDays_Between_Dates(date1, date2));
}
public static int nDays_Between_Dates(String date1, String date2) {
int diffDays = 0;
try {
SimpleDateFormat dates = new SimpleDateFormat("dd-MM-yyyy");
Date startDate = dates.parse(date1);
Date endDate = dates.parse(date2);
long diff = endDate.getTime() - startDate.getTime();
diffDays = (int) (diff / (24 * 60 * 60 * 1000));
} catch (ParseException e) {
e.printStackTrace();
}
return Math.abs(diffDays);
}
}
Output: NDays: 31

public static String dateCalculation(String getTime, String dependTime) {
//Time A is getTime that need to calculate.
//Time B is static time that Time A depend on B Time and calculate the result.
Date date = new Date();
final SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd H:mm:ss");
Date dateObj = null;
Date checkDate = null;
try {
dateObj = sdf.parse(getTime);
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
String checkInDate = dateFormat.format(dateObj).toString();
Date defaultTime = null;
try {
defaultTime = dateFormat.parse(dependTime);
checkDate = dateFormat.parse(checkInDate);
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
try {
if (dateFormat.parse(dateFormat.format(date)).after(defaultTime)) {
long diff = checkDate.getTime() - defaultTime.getTime();
Log.e("Difference", "onBindViewHolder: Difference: " + dateObj + " : " + defaultTime + " : " + diff);
if (diff > 0) {
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000);
return "Late: " + diffHours + " Hour, " + diffMinutes + " Minutes, " + diffSeconds + " Sec";
} else {
return "0";
}
}
} catch (ParseException e) {
e.printStackTrace();
return "0";
}
return "0";
}

Joda time find difference between Hours

I have a date String:
Thu, 15 Jan 2015, 9:56 AM
I convert it into a date variable:
Thu Jan 15 09:56:00 GMT+05:30 2015
using:
String pattern = "EEE, d MMM yyyy, hh:mm a";
try {
date = new SimpleDateFormat(pattern).parse(getPref("refresh", getApplicationContext()));
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Now I have the following function and pass the date variable to this below function:
public static int getDiffHour(Date first) {
int hoursBetween = Hours.hoursBetween(new LocalDate(first), new LocalDate()).getHours();
return hoursBetween;
}
Which always returns 0. What is the possible cause?

try like this,
int diff_hrs = getDiffHours(date,new Date());// pass your date object as startDate and pass current date as your endDate
public int getDiffHours(Date startDate, Date endDate){
Interval interval = new Interval(startDate.getTime(), endDate.getTime());
Period period = interval.toPeriod();
return period.getHours();
}

Try below code:-
public static void main(String[] args) {
String dateStart = "01/14/2012 09:29:58";
String dateStop = "01/15/2012 10:31:48";
//HH converts hour in 24 hours format (0-23), day calculation
SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date d1 = null;
Date d2 = null;
try {
d1 = format.parse(dateStart);
d2 = format.parse(dateStop);
//in milliseconds
long diff = d2.getTime() - d1.getTime();
long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);
System.out.print(diffDays + " days, ");
System.out.print(diffHours + " hours, ");
System.out.print(diffMinutes + " minutes, ");
System.out.print(diffSeconds + " seconds.");
} catch (Exception e) {
e.printStackTrace();
}
}
for more info see below link :-
http://www.mkyong.com/java/how-to-calculate-date-time-difference-in-java/

DateTimeUtils obj = new DateTimeUtils();
SimpleDateFormat simpleDateFormat =
new SimpleDateFormat("EEE, d MMM yyyy, hh:mm a");
try {
Date date1 = simpleDateFormat.parse("Thu Jan 15 09:56:00 GMT+05:30 2015");
Date date2 = simpleDateFormat.parse("Thu Jan 16 09:56:00 GMT+05:30 2015");
obj.printDifference(date1, date2);
} catch (ParseException e) {
e.printStackTrace();
}
}
//1 minute = 60 seconds
//1 hour = 60 x 60 = 3600
//1 day = 3600 x 24 = 86400
public void printDifference(Date startDate, Date endDate){
//milliseconds
long different = endDate.getTime() - startDate.getTime();
System.out.println("startDate : " + startDate);
System.out.println("endDate : "+ endDate);
System.out.println("different : " + different);
long secondsInMilli = 1000;
long minutesInMilli = secondsInMilli * 60;
long hoursInMilli = minutesInMilli * 60;
long daysInMilli = hoursInMilli * 24;
long elapsedDays = different / daysInMilli;
different = different % daysInMilli;
long elapsedHours = different / hoursInMilli;
different = different % hoursInMilli;
long elapsedMinutes = different / minutesInMilli;
different = different % minutesInMilli;
long elapsedSeconds = different / secondsInMilli;
System.out.printf(
"%d days, %d hours, %d minutes, %d seconds%n",
elapsedDays,
elapsedHours, elapsedMinutes, elapsedSeconds);
}