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How can i get `String` date from calendar?

How can i get String date from calendar?
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DAY_OF_MOUNTH, -5); //set now and 5 days to back
I want get String like this(date on interval -5 days to TODAY):
11.03.2015
10.03.2015
.
.
.
07.03.2015
It's possible? How?

you can use for loop and reduce one day from calendar instance and print it
Calendar calendar = Calendar.getInstance();
SimpleDateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy");
for (int index = 1; index <= 5; index++) {
calendar.add(Calendar.DATE, -1);
System.out.println(dateFormat.format(calendar.getTime()));
}
output:
10.03.2015
09.03.2015
08.03.2015
07.03.2015
06.03.2015

You should use the SimpleDateFormat class, as follows.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DAY_OF_MOUNTH -5);
SimpleDateFormat myDateFormat = new SimpleDateFormat("MM.dd.yyyy"); //or ("dd.MM.yyyy"), If you want days before months.
String formattedDate = myDateFormat.format(cal.getTime());

Calendar cal = Calendar.getInstance();
Date date = cal.getTime();
Long beforeTime = date - (5*24*60*60*1000);
Date beforeDate = new Date(beforeTime);
SimpleDateFormat format = new SimpleDateFormat("dd.MM.yyyy");
String s = format.format(beforeDate);
s returns the date in your required format.

SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");
String strdate = sdf.format(calendardate.getTime());

how to convert timestamp into hoursminandsec in java

I have a unix timestamp. I wanted to convert into hours,min and seconds.I wanted to acheive it in java.I tried this .But I am not sure how do i have to concatenate it to hours+min+sec
int day = (int)TimeUnit.SECONDS.toDays(timeStamp);
long hours = TimeUnit.SECONDS.toHours(timeStamp) - (day *24);
long minute = TimeUnit.SECONDS.toMinutes(timeStamp) - (TimeUnit.SECONDS.toHours(timeStamp)* 60);
long second = TimeUnit.SECONDS.toSeconds(timeStamp) - (TimeUnit.SECONDS.toMinutes(timeStamp) *60);
thanks,
Ramya.

You can use the Calendar class for this. You can format the time using SimpleDateFormat
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(timeStamp);
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
String dateString = sdf.format(calendar.getTime());

Date date = new Date ();
date.setTime((long)unix_time*1000);
SimpleDateFormat df = new SimpleDateFormat("hh:mm:ss a",Locale.ENGLISH);
System.out.println(df.format(date));

how to compare two calendar objects?

I want to compare two date objects like this:
String format = "MM/dd/yyyy hh:mm a";
SimpleDateFormat sdf = new SimpleDateFormat(format);
fakeDate = sdf.parse("15/07/2013 11:00 AM");
fakeDate2 = sdf.parse("15/07/2013 12:00 AM");
int diff = date2.getHours() - date1.getHours();
but then I see getHours is deprecated.
So i have used:
Calendar calendar1 = Calendar.getInstance();
calendar.setTime(new Date("15/7/2013 11:00AM"));
Calendar calendar2 = Calendar.getInstance();
calendar.setTime(new Date("11/7/2013 12:00AM"));
calendar1.get(Calendar.HOUR_OF_DAY) - calendar2.get(Calendar.HOUR_OF_DAY)
but then I see the diff is zero. I guess i change the same calendar instance all the time and compare it to itself. no?
how would you write this?

new Date("15/7/2013 11:00AM")
is not the correct way to construct a Date object. It's deprecated also. Use proper SimpleDateFormat as you are doing well in your first example.
The format MM/dd/yyyy hh:mm a is not correct as per the input date string.
It should be like this.
String format = "dd/MM/yyyy hh:mm a";
SimpleDateFormat sdf = new SimpleDateFormat(format);
Date fakeDate = sdf.parse("15/07/2013 11:00 AM");
Date fakeDate2 = sdf.parse("15/07/2013 12:00 AM");
Calendar cal = Calendar.getInstance();
cal.setTime(fakeDate); //set time to first date
int hours1 = cal.get(Calendar.HOUR); // get the hours
cal.setTime(fakeDate2); // set time to second date
int hours2 = cal.get(Calendar.HOUR); // get the hours
System.out.println(hours1 - hours2); // 11 hours

You seemed really confused though it is depreciated this code shall give you a difference of 11 hours which makes sense
SimpleDateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy hh:mm a");
Date fakeDate = dateFormat.parse("15/07/2013 11:00 AM");
Date fakeDate2 = dateFormat.parse("15/07/2013 12:00 AM");
System.out.println(fakeDate.getHours()-fakeDate2.getHours());
Or if you are so interested to use Calendar do it this way
Calendar calendar = Calendar.getInstance();
calendar.setTime(fakeDate);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTime(fakeDate2);
System.out.println(calendar.get(Calendar.HOUR_OF_DAY) -
calendar2.get(Calendar.HOUR_OF_DAY));
You will get the same 11 hours difference or simply do it this way
long millisForNewDate = toDate.getTime();
long millisForOldDate = fromDate.getTime();
long difference = millisForNewDate - millisForOldDate;
int hoursDifferenceBetweenDates = (int)(difference/(1000*60*60));

How to subtract X day from a Date object in Java?

I want to do something like:
Date date = new Date(); // current date
date = date - 300; // substract 300 days from current date and I want to use this "date"
How to do it?

Java 8 and later
With Java 8's date time API change, Use LocalDate
LocalDate date = LocalDate.now().minusDays(300);
Similarly you can have
LocalDate date = someLocalDateInstance.minusDays(300);
Refer to https://stackoverflow.com/a/23885950/260990 for translation between java.util.Date <--> java.time.LocalDateTime
Date in = new Date();
LocalDateTime ldt = LocalDateTime.ofInstant(in.toInstant(), ZoneId.systemDefault());
Date out = Date.from(ldt.atZone(ZoneId.systemDefault()).toInstant());
Java 7 and earlier
Use Calendar's add() method
Calendar cal = Calendar.getInstance();
cal.setTime(dateInstance);
cal.add(Calendar.DATE, -30);
Date dateBefore30Days = cal.getTime();

#JigarJoshi it's the good answer, and of course also #Tim recommendation to use .joda-time.
I only want to add more possibilities to subtract days from a java.util.Date.
Apache-commons
One possibility is to use apache-commons-lang. You can do it using DateUtils as follows:
Date dateBefore30Days = DateUtils.addDays(new Date(),-30);
Of course add the commons-lang dependency to do only date subtract it's probably not a good options, however if you're already using commons-lang it's a good choice. There is also convenient methods to addYears,addMonths,addWeeks and so on, take a look at the api here.
Java 8
Another possibility is to take advantage of new LocalDate from Java 8 using minusDays(long days) method:
LocalDate dateBefore30Days = LocalDate.now(ZoneId.of("Europe/Paris")).minusDays(30);

Simply use this to get date before 300 days, replace 300 with your days:
Date date = new Date(); // Or where ever you get it from
Date daysAgo = new DateTime(date).minusDays(300).toDate();
Here,
DateTime is org.joda.time.DateTime;
Date is java.util.Date

Java 8 Time API:
Instant now = Instant.now(); //current date
Instant before = now.minus(Duration.ofDays(300));
Date dateBefore = Date.from(before);

As you can see HERE there is a lot of manipulation you can do. Here an example showing what you could do!
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
//Add one day to current date.
cal.add(Calendar.DATE, 1);
System.out.println(dateFormat.format(cal.getTime()));
//Substract one day to current date.
cal = Calendar.getInstance();
cal.add(Calendar.DATE, -1);
System.out.println(dateFormat.format(cal.getTime()));
/* Can be Calendar.DATE or
* Calendar.MONTH, Calendar.YEAR, Calendar.HOUR, Calendar.SECOND
*/

With Java 8 it's really simple now:
LocalDate date = LocalDate.now().minusDays(300);
A great guide to the new api can be found here.

In Java 8 you can do this:
Instant inst = Instant.parse("2018-12-30T19:34:50.63Z");
// subtract 10 Days to Instant
Instant value = inst.minus(Period.ofDays(10));
// print result
System.out.println("Instant after subtracting Days: " + value);

I have created a function to make the task easier.
For 7 days after dateString: dateCalculate(dateString,"yyyy-MM-dd",7);
To get 7 days upto dateString: dateCalculate(dateString,"yyyy-MM-dd",-7);
public static String dateCalculate(String dateString, String dateFormat, int days) {
Calendar cal = Calendar.getInstance();
SimpleDateFormat s = new SimpleDateFormat(dateFormat);
try {
cal.setTime(s.parse(dateString));
} catch (ParseException e) {
e.printStackTrace();
}
cal.add(Calendar.DATE, days);
return s.format(cal.getTime());
}

You may also be able to use the Duration class. E.g.
Date currentDate = new Date();
Date oneDayFromCurrentDate = new Date(currentDate.getTime() - Duration.ofDays(1).toMillis());

You can easily subtract with calendar with SimpleDateFormat
public static String subtractDate(String time,int subtractDay) throws ParseException {
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.ENGLISH);
cal.setTime(sdf.parse(time));
cal.add(Calendar.DATE,-subtractDay);
String wantedDate = sdf.format(cal.getTime());
Log.d("tag",wantedDate);
return wantedDate;
}

Get yesterday's date using Date [duplicate]

This question already has answers here:
How to check if a date Object equals yesterday?
(9 answers)
Closed 8 years ago.
The following function produces today's date; how can I make it produce only yesterday's date?
private String toDate() {
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date date = new Date();
return dateFormat.format(date).toString();
}
This is the output:
2012-07-10
I only need yesterday's date like below. Is it possible to do this in my function?
2012-07-09

Update
There has been recent improvements in datetime API with JSR-310.
Instant now = Instant.now();
Instant yesterday = now.minus(1, ChronoUnit.DAYS);
System.out.println(now);
System.out.println(yesterday);
https://ideone.com/91M1eU
Outdated answer
You are subtracting the wrong number:
Use Calendar instead:
private Date yesterday() {
final Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, -1);
return cal.getTime();
}
Then, modify your method to the following:
private String getYesterdayDateString() {
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
return dateFormat.format(yesterday());
}
See
IDEOne Demo

You can do following:
private Date getMeYesterday(){
return new Date(System.currentTimeMillis()-24*60*60*1000);
}
Note: if you want further backward date multiply number of day with 24*60*60*1000 for example:
private Date getPreviousWeekDate(){
return new Date(System.currentTimeMillis()-7*24*60*60*1000);
}
Similarly, you can get future date by adding the value to System.currentTimeMillis(), for example:
private Date getMeTomorrow(){
return new Date(System.currentTimeMillis()+24*60*60*1000);
}

Calendar cal = Calendar.getInstance();
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
System.out.println("Today's date is "+dateFormat.format(cal.getTime()));
cal.add(Calendar.DATE, -1);
System.out.println("Yesterday's date was "+dateFormat.format(cal.getTime()));
Use Calender Api

Try this one:
private String toDate() {
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
// Create a calendar object with today date. Calendar is in java.util pakage.
Calendar calendar = Calendar.getInstance();
// Move calendar to yesterday
calendar.add(Calendar.DATE, -1);
// Get current date of calendar which point to the yesterday now
Date yesterday = calendar.getTime();
return dateFormat.format(yesterday).toString();
}

Try this;
public String toDate() {
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, -1);
return dateFormat.format(cal.getTime());
}

changed from your code :
private String toDate(long timestamp) {
Date date = new Date (timestamp * 1000 - 24 * 60 * 60 * 1000);
return new SimpleDateFormat("yyyy-MM-dd").format(date).toString();
}
but you do better using calendar.

There is no direct function to get yesterday's date.
To get yesterday's date, you need to use Calendar by subtracting -1.

Calendar cal = Calendar.getInstance();
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
System.out.println("Today's date is "+dateFormat.format(cal.getTime()));
cal.add(Calendar.DATE, -1);
System.out.println("Yesterday's date was "+dateFormat.format(cal.getTime()));