Compare if a date is less than 24 hours before - java

I am trying to compare two calendars in java to decide if one of them is >= 24 hours ago. I am unsure on the best approach to accomplish this.
// get today's date
Date today = new Date();
Calendar currentDate = Calendar.getInstance();
currentDate.setTime(today);
// get last update date
Date lastUpdate = profile.getDateLastUpdated().get(owner);
Calendar lastUpdatedCalendar = Calendar.getInstance();
lastUpdatedCalendar(lastUpdate);
// compare that last hotted was < 24 hrs ago from today?

tl;dr
Instant now = Instant.now();
Boolean isWithinPrior24Hours =
( ! yourJUDate.toInstant().isBefore( now.minus( 24 , ChronoUnit.HOURS) ) )
&&
( yourJUDate.toInstant().isBefore( now )
) ;
Details
The old date-time classes (java.util.Date/.Calendar, java.text.SimpleDateFormat, etc.) have proven to be be confusing and flawed. Avoid them.
For Java 8 and later, use java.time framework built into Java. For earlier Java, add the Joda-Time framework to your project.
You can easily convert between a java.util.Date and either framework.
java.time
The java.time framework built into Java 8 and later supplants the troublesome old java.util.Date/.Calendar classes. The new classes are inspired by the highly successful Joda-Time framework, intended as its successor, similar in concept but re-architected. Defined by JSR 310. Extended by the ThreeTen-Extra project. See the Tutorial.
The Instant class represents a moment on the timeline in UTC. If you meant to ask for literally 24 hours rather than "a day", then Instant is all we need.
Instant then = yourJUDate.toInstant();
Instant now = Instant.now();
Instant twentyFourHoursEarlier = now.minus( 24 , ChronoUnit.HOURS );
// Is that moment (a) not before 24 hours ago, AND (b) before now (not in the future)?
Boolean within24Hours = ( ! then.isBefore( twentyFourHoursEarlier ) ) && then.isBefore( now ) ;
If you meant "a day" rather than 24 hours, then we need to consider time zone. A day is determined locally, within a time zone. Daylight Saving Time (DST) and other anomalies mean a day is not always 24 hours long.
Instant then = yourJUDate.toInstant();
ZoneId zoneId = ZoneId.of( "America/Montreal" );
ZonedDateTime now = ZonedDateTime.now( zoneId );
ZonedDateTime oneDayAgo = now.minusDays( 1 );
Boolean within24Hours = ( ! then.isBefore( oneDayAgo ) ) && then.isBefore( now ) ;
Another approach would use the Interval class found in the ThreeTen-Extra project. That class represents a pair of Instant objects. The class offers methods such as contains to perform comparisons.
Joda-Time
The Joda-Time library works in a similar fashion to java.time, having been its inspiration.
DateTime dateTime = new DateTime( yourDate ); // Convert java.util.Date to Joda-Time DateTime.
DateTime yesterday = DateTime.now().minusDays(1);
boolean isBeforeYesterday = dateTime.isBefore( yesterday );
Or, in one line:
boolean isBeforeYesterday = new DateTime( yourDate).isBefore( DateTime.now().minusDays(1) );

you could use Date.getTime(), here's an example:
public final static long MILLIS_PER_DAY = 24 * 60 * 60 * 1000L;
public static void main(String args[]) throws Exception {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date1 = sdf.parse("2009-12-31");
Date date2 = sdf.parse("2010-01-31");
boolean moreThanDay = Math.abs(date1.getTime() - date2.getTime()) > MILLIS_PER_DAY;
System.out.println(moreThanDay);
}

You can check localDateTime whether its in 24 hours or not, depending on zone offset parameter like following the example.
#Test
public void checkIsWithin24Hours() {
final ZoneOffset zoneOffset = ZoneOffset.UTC;
final LocalDateTime now = LocalDateTime.now(zoneOffset);
final LocalDateTime after = LocalDateTime.now(zoneOffset).plusHours(5);
final long nowHours = TimeUnit.MILLISECONDS.toHours(now.toInstant(zoneOffset).toEpochMilli());
final long afterFiveHours = TimeUnit.MILLISECONDS.toHours(after.toInstant(zoneOffset).toEpochMilli());
assertThat(afterFiveHours - nowHours <= 24).isTrue();
}

Related

How to modify java Date to a specific time? [duplicate]

This question already has answers here:
Getting specific date with timezone in Java
(1 answer)
how to get dateTime based on hour and minute
(4 answers)
Closed 1 year ago.
I am running a script in Jenkins. One piece of the script need to run at 07:00:00 Eastern Time.
The job is already scheduled on specific days and time. The job starts at 6am, but need to wait until 7am to run the next step
Using java, I can get current time/date using:
Date currentDate = new Date()
I think I need to compare currentDate with today's date at 7am so I can know how many seconds there is until 7am and put my build to sleep for that time.
My question is, how can I generate today's date at 7am?
Avoid using the terrible Date class. The legacy date-time classes were years ago supplanted by the modern java.time classes defined in JSR 310.
Capture the current moment as seen in your particular time zone.
ZoneId z = ZoneId.of( "America/New_York" ) ;
ZonedDateTime zdt = ZonedDateTime.now( z ) ;
Define your target.
LocalTime targetTime = LocalTime.of( 7 , 0 ) ;
Adjust to that time.
ZonedDateTime zdtTarget = zdt.with( targetTime ) ;
If that moment has passed, move to next day.
if( ! zdt.isBefore( zdtTarget ) ) {
zdtTarget = zdt.toLocalDate().plusDays( 1 ).atStartOfDay( z ).with( targetTime ) ;
}
Determine time to elapse.
Duration d = Duration.between( zdt.toInstant() , zdtTarget.toInstant() ) ;
Interrogate the duration object for whatever you need. For example, milliseconds:
long millis = d.toMillis() ;
Thread.sleep( millis ) ;
If you must use a java.until.Date for code not yet updated to java.time, you can convert.
java.until.Date date = Date.from( zdtTarget.toInstant() ) ;
Great question. It's easier to first create a Calendar object to set up the time, date and other custom inputs, then convert that to a Date object using the <CALENDAR_OBJECT>.getTime() member function.
EX: to get a Date object of 7 am today(10/25/2021) do the following:
Calendar cal = Calendar.getInstance(); // Calendar constructor
cal.set(Calendar.YEAR, 2021);
cal.set(Calendar.MONTH, 10);
cal.set(Calendar.DAY_OF_MONTH, 25);
cal.set(Calendar.HOUR_OF_DAY,7);
cal.set(Calendar.MINUTE,00);
cal.set(Calendar.SECOND,0);
cal.set(Calendar.MILLISECOND,0);
Date d = cal.getTime(); // convert to Date obj
For more info on the Calendar obj look at some documentation by Oracle (https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html)

Get minutes of date using Joda-Time

Following zulu date string is given:
2013-12-18T23:41:54.959Z
And I want to convert this to GMT and retrieve the minutes using Joda-Time. I build following method:
public static int minutesFromDateString(final String s){
DateTimeFormatter formatter = DateTimeFormat.forPattern("HH:mm").withZone(DateTimeZone.forID("Europe/Berlin"));
DateTime dt = formatter.parseDateTime(s);
Calendar calendar = Calendar.getInstance();
calendar.setTime(dt.toDate());
return calendar.get(Calendar.MINUTE);
}
However this returns an error:
12-22 16:04:11.940: E/AndroidRuntime(6433):
java.lang.IllegalArgumentException: Invalid format:
"2013-12-18T23:41:54.959Z" is malformed at "13-12-18T23:41:54.959Z"
Any ideas whats wrong?
You aren't using a valid pattern. Your pattern says it is looking for HH:mm, your real string is far more complex. Look at the DateTimeFormat docs. It looks like you want something like this: "yyyy-mm-dd'T'HH:mm:ss.SSS'Z'"
Just set proper pattern: "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
In your case:
public static int minutesFromDateString(final String s){
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ").withZone(DateTimeZone.forID("Europe/Berlin"));
DateTime dt = formatter.parseDateTime(s);
Calendar calendar = Calendar.getInstance();
calendar.setTime(dt.toDate());
return calendar.get(Calendar.MINUTE);
}
Output:
41
See docs HERE
The answer by PearsonArtPhoto is correct. To add more…
Joda-Time
With Joda-Time, no need for format pattern, and no need for Calendar class. You are working too hard.
The DateTime class takes an ISO 8601 string directly in its constructor.
Call the getMinuteOfHour method on a DateTime to extract just that portion.
If you want UTC/GMT rather than a specific time zone, pass the built-in constant, DateTimeZone.UTC. Be aware that time zone could affect your minute-of-hour. Not all time zones adjust by full hours. India for example has an offset of five and a half hours ahead of UTC/GMT (+05:30).
String input = "2013-12-18T23:41:54.959Z";
DateTimeZone timeZone = DateTimeZone.forID( "Europe/Berlin" ); // Or, DateTimeZone.UTC;
DateTime dateTime = new DateTime( input, timeZone );
int minuteOfHour = dateTime.getMinuteOfHour();
Dump to console…
System.out.println( "dateTime: " + dateTime );
System.out.println( "minuteOfHour: " + minuteOfHour );
When run…
dateTime: 2013-12-19T00:41:54.959+01:00
minuteOfHour: 41
java.time
Joda-Time has been officially replaced by the java.time framework built into Java 8 and later. While Joda-Time continues to be updated, future work will go into the java.time classes and their extension, ThreeTen-Extra project.
Much of java.time has been back-ported to Java 6 & 7 in the ThreeTen-Backport project. That work is adapted to Android in the ThreeTenABP project.
The discussion above applies to a java.time solution. An Instant is a moment on the timeline in UTC. Apply a time zone ZoneId to get a ZonedDateTime.
String input = "2013-12-18T23:41:54.959Z";
Instant instant = Instant.parse( input );
ZoneId zoneId = ZoneId.of( "Europe/Berlin" ); // Or, ZoneOffset.UTC;
ZonedDateTime zdt = ZonedDateTime.ofInstant( instant, zoneId );
int minuteOfHour = zdt.getMinute(); // Gets the minute-of-hour field.

Java Time calculation

So my method receives a time in 24 hour format ("HH:MM:SS") and returns a string the difference time. If it's 2:00PM local time I should be able to send it "16:30:00"(4:30PM) and get the output "2 hours, 30 mins". But the code has some problem, and I am just a beginner and I need help to fix it.
The problem is if the time is 4:40PM, and I sent it "17:00:00"(5:00PM) it returns the message:
12 hours, 20 minutes instead of 0 hours, 20 minutes.
The other problem is if I sent it the current time, it would return "12 hours" away, and not 24 like it should.
Please keep in mind I am only a beginner at java and math really isn't my thing, so any help is highly appreciated. Thanks.
private static String timeUntil(String distanceTime) {
String returnMsg = null;
try {
SimpleDateFormat sdfDate = new SimpleDateFormat("hh:mm:ss");
Date now = new Date();
java.text.DateFormat df = new java.text.SimpleDateFormat("hh:mm:ss");
Date date1 = df.parse(sdfDate.format(now));
Date date2 = df.parse(distanceTime);
long diff = date2.getTime() - date1.getTime();
int timeInSeconds = (int) (diff / 1000);
int hours, minutes;
hours = timeInSeconds / 3600;
timeInSeconds = timeInSeconds - (hours * 3600);
minutes = timeInSeconds / 60;
if (hours >= 0) {
returnMsg = hours + " hours" +
"\n" + minutes + " mins";
} else {
returnMsg = minutes + " mins";
}
} catch (Exception e) {
e.printStackTrace();
}
return returnMsg;
}
In your date format, hh is used for 12-hour time. Use HH for 24-hour time:
new SimpleDateFormat("HH:mm:ss");
Code review comments...
Most of the Date class' methods are deprecated. You should consider using Calendar (GregorianCalendar) instead of Date.
Your variable names often lack meaning - you have to know the purpose of the variable to know its meaning. Your code will be more maintainable if you use better variable names. df could be renamed "format" or "dateFormat".
You create a Date object 'now', then you pass it through your df DateFormat instance, hten through your sdfDate instance, to convert it back to a Date. This is unnecessary. Replace this with Date date1 = new Date(); and remove Date now = new Date();. Simiilarly, I've seen very difficult to diagnose errors when converting between units, so you should change diff to indicate that it's milliseconds, like diff_ms. And you should keep names consistent - you change from "different" (diff) to "timeInSeconds". They should both be "timeInXxx" or "diff_xx". the distanceTime parameter should be renamed something like futureTime
You do a bunch of math to determine the difference between two times, but there are libraries that will do this for you. Google for "java difference between two dates" and find many answers.
Your code always assumes that the second time occurs after "now". This should be included in a comment at the top of your method.
When you instantiate date1 and date2, they're both probably for the same day. Try debugging or at least printing the objects to stdout immediately after they're created to see if this is the case. Is this what you really want?
Your code doesn't handle leap year.
Instead of handling all of the time conversions yourself, why don't you look for a library that does it for you?
This is your fixed code. I have changed the date format to HH:mm:ss and also your calculation logic. Try it and let us know
private static String timeUntil(String distanceTime) {
String returnMsg = null;
try {
SimpleDateFormat sdfDate = new SimpleDateFormat("HH:mm:ss");
Date now = new Date();
java.text.DateFormat df = new java.text.SimpleDateFormat("HH:mm:ss");
Date date1 = df.parse(sdfDate.format(now));
Date date2 = df.parse(distanceTime);
long diff = date2.getTime() - date1.getTime();
int timeInSeconds = (int) (diff / 1000);
int hours, minutes;
hours = timeInSeconds / 3600;
timeInSeconds = timeInSeconds - (hours * 3600);
minutes = timeInSeconds / 60;
if (hours != 0) {
returnMsg = hours + " hours" +
"\n" + minutes + " mins";
} else {
returnMsg = minutes + " mins";
}
} catch (Exception e) {
e.printStackTrace();
}
return returnMsg;
}
Here is an example which is more robust and uses Java more modern date functions. I could go point by point and point at all the thing you could have done better in your example, but sometimes its easier to give you a good example and let you glean what you can from other people code as far as good style.
import java.util.Calendar;
public class testSpace {
public static void main (String ... args){
System.out.println(timeUntil("00:12:12"));
}
private static String timeUntil(String distanceTime){
String[] times = distanceTime.split(":");
Calendar now = Calendar.getInstance();
Calendar then = Calendar.getInstance();
then.set(Calendar.SECOND, Integer.parseInt(times[2]));
then.set(Calendar.MINUTE, Integer.parseInt(times[1]));
then.set(Calendar.HOUR, Integer.parseInt(times[0]) % 12);
then.set(Calendar.AM_PM, (Integer.parseInt(times[0]) >= 12 ) ? Calendar.PM : Calendar.AM);
boolean isFuture = (then.getTimeInMillis() > now.getTimeInMillis());
long interval = (isFuture)
? then.getTimeInMillis() - now.getTimeInMillis()
: now.getTimeInMillis() - then.getTimeInMillis();
return ((isFuture) ? "" : "-") + millToTime(interval);
}
public static long MILLISECOND_PER_HOUR = 1000*60*60;
public static long MILLISECOND_PER_MIN = 1000*60;
public static long MILLISECOND_PER_SECOND = 1000;
public static String millToTime(long mill){
long hours = mill / MILLISECOND_PER_HOUR;
long mins = (mill % MILLISECOND_PER_HOUR) / MILLISECOND_PER_MIN;
long sec = ((mill % MILLISECOND_PER_HOUR) % MILLISECOND_PER_MIN) / MILLISECOND_PER_SECOND;
return String.format("%d:%d:%d", hours, mins, sec);
}
}
tl;dr
For time-of-day only, without a date or time zone.
LocalTime start = LocalTime.of( "16:40" ) ;
LocalTime stop = LocalTime.of( "17:00" ) ;
Duration d = Duration.between( start , stop ) ;
PT20M
Or, for date-time in a zone.
ZoneId z = ZoneId.of( "America/Montreal" )
ZonedDateTime zdtNow = ZonedDateTime.now( z );
ZonedDateTime zdtThen =
ZonedDateTime.of( // Pass a LocalDate, LocalTime, ZoneId.
zdtNow.toLocalDate() , // Same date…
LocalTime.parse( "16:30:00" ) , // … but different time-of-day.
z
)
Duration d = Duration.between( zdtNow , zdtThen ) ;
PT2H30M
Details
You are using old date-time classes, now legacy, supplanted by the java.time classes.
LocalTime
You are incorrectly using a date-time class for a time-of-day-only value. Instead use the LocalTime class. And use a span-of-time class when calculating elapsed time.
String input = "16:30:00" ;
LocalTime lt = LocalTime.parse( input );
Instant
The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).
Instant instant = Instant.now();
ZonedDateTime
Determining a wall-clock time requires a time zone. Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime zdtNow = instant.atZone( z ); // Adjusted into your time zone.
Now construct a ZonedDateTime for your given input time-of-day.
ZonedDateTime zdtTarget = ZonedDateTime.of( zdtNow.toLocalDate() , lt , z );
Duration
Use Duration to represent elapsed time not attached to the timeline.
Duration d = Duration.between( zdtNow , zdtTarget );
Note that the duration will be a negative amount if the specified time-of-day is earlier than the current time-of-day.
ISO 8601 string for duration
To get a String describing the hours, minutes, etc. of that span of time, simply call toString to generate a String in standard ISO 8601 format of PnYnMnDTnHnMnS where P marks the beginning and T separates the years-month-days from hours-minutes-seconds.
If the current time were 14:00:00 in the same zone, the output would be:
PT2H30M
Getter methods
Oddly, in Java 8 this class Duration lacks any getter methods for the parts such as 2 for hours and 30 for minutes. Remedied in Java 9 with methods such as toHoursPart and toMinutesPart.
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to java.time.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8 and SE 9 and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
See How to use….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How to obtain the start time and end time of a day?

How to obtain the start time and end time of a day?
code like this is not accurate:
private Date getStartOfDay(Date date) {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DATE);
calendar.set(year, month, day, 0, 0, 0);
return calendar.getTime();
}
private Date getEndOfDay(Date date) {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DATE);
calendar.set(year, month, day, 23, 59, 59);
return calendar.getTime();
}
It is not accurate to the millisecond.
Java 8
public static Date atStartOfDay(Date date) {
LocalDateTime localDateTime = dateToLocalDateTime(date);
LocalDateTime startOfDay = localDateTime.with(LocalTime.MIN);
return localDateTimeToDate(startOfDay);
}
public static Date atEndOfDay(Date date) {
LocalDateTime localDateTime = dateToLocalDateTime(date);
LocalDateTime endOfDay = localDateTime.with(LocalTime.MAX);
return localDateTimeToDate(endOfDay);
}
private static LocalDateTime dateToLocalDateTime(Date date) {
return LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
}
private static Date localDateTimeToDate(LocalDateTime localDateTime) {
return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
}
Update: I've added these 2 methods to my Java Utility Classes here
DateUtils.atStartOfDay
DateUtils.atEndOfDay
It is in the Maven Central Repository at:
<dependency>
<groupId>com.github.rkumsher</groupId>
<artifactId>utils</artifactId>
<version>1.3</version>
</dependency>
Java 7 and Earlier
With Apache Commons
public static Date atEndOfDay(Date date) {
return DateUtils.addMilliseconds(DateUtils.ceiling(date, Calendar.DATE), -1);
}
public static Date atStartOfDay(Date date) {
return DateUtils.truncate(date, Calendar.DATE);
}
Without Apache Commons
public Date atEndOfDay(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, 23);
calendar.set(Calendar.MINUTE, 59);
calendar.set(Calendar.SECOND, 59);
calendar.set(Calendar.MILLISECOND, 999);
return calendar.getTime();
}
public Date atStartOfDay(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
return calendar.getTime();
}
tl;dr
LocalDate // Represents an entire day, without time-of-day and without time zone.
.now( // Capture the current date.
ZoneId.of( "Asia/Tokyo" ) // Returns a `ZoneId` object.
) // Returns a `LocalDate` object.
.atStartOfDay( // Determines the first moment of the day as seen on that date in that time zone. Not all days start at 00:00!
ZoneId.of( "Asia/Tokyo" )
) // Returns a `ZonedDateTime` object.
Start of day
Get the full length of the today as seen in a time zone.
Using Half-Open approach, where the beginning is inclusive while the ending is exclusive. This approach solves the flaw in your code that fails to account for the very last second of the day.
ZoneId zoneId = ZoneId.of( "Africa/Tunis" ) ;
LocalDate today = LocalDate.now( zoneId ) ;
ZonedDateTime zdtStart = today.atStartOfDay( zoneId ) ;
ZonedDateTime zdtStop = today.plusDays( 1 ).atStartOfDay( zoneId ) ;
zdtStart.toString() = 2020-01-30T00:00+01:00[Africa/Tunis]
zdtStop.toString() = 2020-01-31T00:00+01:00[Africa/Tunis]
See the same moments in UTC.
Instant start = zdtStart.toInstant() ;
Instant stop = zdtStop.toInstant() ;
start.toString() = 2020-01-29T23:00:00Z
stop.toString() = 2020-01-30T23:00:00Z
If you want the entire day of a date as seen in UTC rather than in a time zone, use OffsetDateTime.
LocalDate today = LocalDate.now( ZoneOffset.UTC ) ;
OffsetDateTime odtStart = today.atTime( OffsetTime.MIN ) ;
OffsetDateTime odtStop = today.plusDays( 1 ).atTime( OffsetTime.MIN ) ;
odtStart.toString() = 2020-01-30T00:00+18:00
odtStop.toString() = 2020-01-31T00:00+18:00
These OffsetDateTime objects will already be in UTC, but you can call toInstant if you need such objects which are always in UTC by definition.
Instant start = odtStart.toInstant() ;
Instant stop = odtStop.toInstant() ;
start.toString() = 2020-01-29T06:00:00Z
stop.toString() = 2020-01-30T06:00:00Z
Tip: You may be interested in adding the ThreeTen-Extra library to your project to use its Interval class to represent this pair of Instant objects. This class offers useful methods for comparison such as abuts, overlaps, contains, and more.
Interval interval = Interval.of( start , stop ) ;
interval.toString() = 2020-01-29T06:00:00Z/2020-01-30T06:00:00Z
Half-Open
The answer by mprivat is correct. His point is to not try to obtain end of a day, but rather compare to "before start of next day". His idea is known as the "Half-Open" approach where a span of time has a beginning that is inclusive while the ending is exclusive.
The current date-time frameworks of Java (java.util.Date/Calendar and Joda-Time) both use milliseconds from the epoch. But in Java 8, the new JSR 310 java.time.* classes use nanoseconds resolution. Any code you wrote based on forcing the milliseconds count of last moment of day would be incorrect if switched to the new classes.
Comparing data from other sources becomes faulty if they employ other resolutions. For example, Unix libraries typically employ whole seconds, and databases such as Postgres resolve date-time to microseconds.
Some Daylight Saving Time changes happen over midnight which might further confuse things.
Joda-Time 2.3 offers a method for this very purpose, to obtain first moment of the day: withTimeAtStartOfDay(). Similarly in java.time, LocalDate::atStartOfDay.
Search StackOverflow for "joda half-open" to see more discussion and examples.
See this post, Time intervals and other ranges should be half-open, by Bill Schneider.
Avoid legacy date-time classes
The java.util.Date and .Calendar classes are notoriously troublesome. Avoid them.
Use java.time classes. The java.time framework is the official successor of the highly successful Joda-Time library.
java.time
The java.time framework is built into Java 8 and later. Back-ported to Java 6 & 7 in the ThreeTen-Backport project, further adapted to Android in the ThreeTenABP project.
An Instant is a moment on the timeline in UTC with a resolution of nanoseconds.
Instant instant = Instant.now();
Apply a time zone to get the wall-clock time for some locality.
ZoneId zoneId = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.ofInstant( instant , zoneId );
To get the first moment of the day go through the LocalDate class and its atStartOfDay method.
ZonedDateTime zdtStart = zdt.toLocalDate().atStartOfDay( zoneId );
Using Half-Open approach, get first moment of following day.
ZonedDateTime zdtTomorrowStart = zdtStart.plusDays( 1 );
Currently the java.time framework lacks an Interval class as described below for Joda-Time. However, the ThreeTen-Extra project extends java.time with additional classes. This project is the proving ground for possible future additions to java.time. Among its classes is Interval. Construct an Interval by passing a pair of Instant objects. We can extract an Instant from our ZonedDateTime objects.
Interval today = Interval.of( zdtStart.toInstant() , zdtTomorrowStart.toInstant() );
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 brought some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android (26+) bundle implementations of the java.time classes.
For earlier Android (<26), a process known as API desugaring brings a subset of the java.time functionality not originally built into Android.
If the desugaring does not offer what you need, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above) to Android. See How to use ThreeTenABP….
Joda-Time
UPDATE: The Joda-Time project is now in maintenance-mode, and advises migration to the java.time classes. I am leaving this section intact for history.
Joda-Time has three classes to represent a span of time in various ways: Interval, Period, and Duration. An Interval has a specific beginning and ending on the timeline of the Universe. This fits our need to represent "a day".
We call the method withTimeAtStartOfDay rather than set time of day to zeros. Because of Daylight Saving Time and other anomalies the first moment of the day may not be 00:00:00.
Example code using Joda-Time 2.3.
DateTimeZone timeZone = DateTimeZone.forID( "America/Montreal" );
DateTime now = DateTime.now( timeZone );
DateTime todayStart = now.withTimeAtStartOfDay();
DateTime tomorrowStart = now.plusDays( 1 ).withTimeAtStartOfDay();
Interval today = new Interval( todayStart, tomorrowStart );
If you must, you can convert to a java.util.Date.
java.util.Date date = todayStart.toDate();
in getEndOfDay, you can add:
calendar.set(Calendar.MILLISECOND, 999);
Although mathematically speaking, you can't specify the end of a day other than by saying it's "before the beginning of the next day".
So instead of saying, if(date >= getStartOfDay(today) && date <= getEndOfDay(today)), you should say: if(date >= getStartOfDay(today) && date < getStartOfDay(tomorrow)). That is a much more solid definition (and you don't have to worry about millisecond precision).
java.time
Using java.time framework built into Java 8.
import java.time.LocalTime;
import java.time.LocalDateTime;
LocalDateTime now = LocalDateTime.now(); // 2015-11-19T19:42:19.224
// start of a day
now.with(LocalTime.MIN); // 2015-11-19T00:00
now.with(LocalTime.MIDNIGHT); // 2015-11-19T00:00
// end of a day
now.with(LocalTime.MAX); // 2015-11-19T23:59:59.999999999
Java 8 or ThreeTenABP
ZonedDateTime
ZonedDateTime curDate = ZonedDateTime.now();
public ZonedDateTime startOfDay() {
return curDate
.toLocalDate()
.atStartOfDay()
.atZone(curDate.getZone())
.withEarlierOffsetAtOverlap();
}
public ZonedDateTime endOfDay() {
ZonedDateTime startOfTomorrow =
curDate
.toLocalDate()
.plusDays(1)
.atStartOfDay()
.atZone(curDate.getZone())
.withEarlierOffsetAtOverlap();
return startOfTomorrow.minusSeconds(1);
}
// based on https://stackoverflow.com/a/29145886/1658268
LocalDateTime
LocalDateTime curDate = LocalDateTime.now();
public LocalDateTime startOfDay() {
return curDate.atStartOfDay();
}
public LocalDateTime endOfDay() {
return startOfTomorrow.atTime(LocalTime.MAX); //23:59:59.999999999;
}
// based on https://stackoverflow.com/a/36408726/1658268
I hope that helps someone.
Additional way of finding start of day with java8 java.time.ZonedDateTime instead of going through LocalDateTime is simply truncating the input ZonedDateTime to DAYS:
zonedDateTimeInstance.truncatedTo( ChronoUnit.DAYS );
I tried this code and it works well!
final ZonedDateTime now = ZonedDateTime.now(ZoneOffset.UTC);
final ZonedDateTime startofDay =
now.toLocalDate().atStartOfDay(ZoneOffset.UTC);
final ZonedDateTime endOfDay =
now.toLocalDate().atTime(LocalTime.MAX).atZone(ZoneOffset.UTC);
For java 8 the following single line statements are working. In this example I use UTC timezone. Please consider to change TimeZone that you currently used.
System.out.println(new Date());
final LocalDateTime endOfDay = LocalDateTime.of(LocalDate.now(), LocalTime.MAX);
final Date endOfDayAsDate = Date.from(endOfDay.toInstant(ZoneOffset.UTC));
System.out.println(endOfDayAsDate);
final LocalDateTime startOfDay = LocalDateTime.of(LocalDate.now(), LocalTime.MIN);
final Date startOfDayAsDate = Date.from(startOfDay.toInstant(ZoneOffset.UTC));
System.out.println(startOfDayAsDate);
If no time difference with output. Try: ZoneOffset.ofHours(0)
Another one solution which does not depend on any framework is:
static public Date getStartOfADay(Date day) {
final long oneDayInMillis = 24 * 60 * 60 * 1000;
return new Date(day.getTime() / oneDayInMillis * oneDayInMillis);
}
static public Date getEndOfADay(Date day) {
final long oneDayInMillis = 24 * 60 * 60 * 1000;
return new Date((day.getTime() / oneDayInMillis + 1) * oneDayInMillis - 1);
}
Note that it returns UTC based time
I know it's a bit late, but in case of Java 8, if you are using OffsetDateTime (which offers a lot of advantages, such as TimeZone, Nanoseconds, etc.), you can use the following code:
OffsetDateTime reallyEndOfDay = someDay.withHour(23).withMinute(59).withSecond(59).withNano(999999999);
// output: 2019-01-10T23:59:59.999999999Z
private Date getStartOfDay(Date date) {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DATE);
calendar.setTimeInMillis(0);
calendar.set(year, month, day, 0, 0, 0);
return calendar.getTime();
}
private Date getEndOfDay(Date date) {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DATE);
calendar.setTimeInMillis(0);
calendar.set(year, month, day, 23, 59, 59);
return calendar.getTime();
}
calendar.setTimeInMillis(0); gives you accuracy upto milliseconds
Shortest answer, given your timezone being TZ:
LocalDateTime start = LocalDate.now(TZ).atStartOfDay()
LocalDateTime end = start.plusDays(1)
Compare using isAfter() and isBefore() methods, or convert it using toEpochSecond() or toInstant() methods.
The following code takes the OP's original formula, and adjusts for the ms inexactness:
private static Date getStartOfDay() {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DATE);
calendar.set(year, month, day, 0, 0, 0);
long approximateTimestamp = calendar.getTime().getTime();
long extraMillis = (approximateTimestamp % 1000);
long exactTimestamp = approximateTimestamp - extraMillis;
return new Date(exactTimestamp);
}
private static Date getEndOfDay() {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DATE);
calendar.set(year, month, day, 23, 59, 59);
long approximateTimestamp = calendar.getTime().getTime();
long extraMillis = (approximateTimestamp % 1000);
long exactTimestamp = approximateTimestamp - extraMillis + 999;
return new Date(exactTimestamp);
}
Unlike many other answers on this thread, it is compatible with older versions of Java and Android APIs.
I had several inconveniences with all the solutions because I needed the type of Instant variable and the Time Zone always interfered changing everything, then combining solutions I saw that this is a good option.
LocalDate today = LocalDate.now();
Instant startDate = Instant.parse(today.toString()+"T00:00:00Z");
Instant endDate = Instant.parse(today.toString()+"T23:59:59Z");
and we have as a result
startDate = 2020-01-30T00:00:00Z
endDate = 2020-01-30T23:59:59Z
I hope it helps you
I think the easiest would be something like:
// Joda Time
DateTime dateTime=new DateTime();
StartOfDayMillis = dateTime.withMillis(System.currentTimeMillis()).withTimeAtStartOfDay().getMillis();
EndOfDayMillis = dateTime.withMillis(StartOfDayMillis).plusDays(1).minusSeconds(1).getMillis();
These millis can be then converted into Calendar,Instant or LocalDate as per your requirement with Joda Time.
public static Date beginOfDay(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
return cal.getTime();
}
public static Date endOfDay(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.set(Calendar.HOUR_OF_DAY, 23);
cal.set(Calendar.MINUTE, 59);
cal.set(Calendar.SECOND, 59);
cal.set(Calendar.MILLISECOND, 999);
return cal.getTime();
}
Date date = new Date();
LocalDateTime localDateTime = LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
LocalDateTime startOfDay = localDateTime.with(LocalTime.MIN);
LocalDateTime endOfDay = localDateTime.with(LocalTime.MAX);
Timestamp:
Timestamp startTs = Timestamp.valueOf(startOfDay);
Timestamp endTs = Timestamp.valueOf(endOfDay);

Why is the month changed to 50 after I added 10 minutes?

I have this date object:
SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd HH:mm");
Date d1 = df.parse(interviewList.get(37).getTime());
value of d1 is Fri Jan 07 17:40:00 PKT 2011
Now I am trying to add 10 minutes to the date above.
Calendar cal = Calendar.getInstance();
cal.setTime(d1);
cal.add(Calendar.MINUTE, 10);
String newTime = df.format(cal.getTime());
Value of newTime changes to 2011-50-07 17:50
but it should be 07-01-2011 17:50.
It adds minutes correctly but it also changes month, don't know why!
The issue for you is that you are using mm. You should use MM. MM is for month and mm is for minutes. Try with yyyy-MM-dd HH:mm
Other approach:
It can be as simple as this (other option is to use joda-time)
static final long ONE_MINUTE_IN_MILLIS=60000;//millisecs
Calendar date = Calendar.getInstance();
long t= date.getTimeInMillis();
Date afterAddingTenMins=new Date(t + (10 * ONE_MINUTE_IN_MILLIS));
you can use DateUtils class in org.apache.commons.lang3.time package
int addMinuteTime = 5;
Date targetTime = new Date(); //now
targetTime = DateUtils.addMinutes(targetTime, addMinuteTime); //add minute
Convenience method for implementing #Pangea's answer:
/*
* Convenience method to add a specified number of minutes to a Date object
* From: http://stackoverflow.com/questions/9043981/how-to-add-minutes-to-my-date
* #param minutes The number of minutes to add
* #param beforeTime The time that will have minutes added to it
* #return A date object with the specified number of minutes added to it
*/
private static Date addMinutesToDate(int minutes, Date beforeTime){
final long ONE_MINUTE_IN_MILLIS = 60000;//millisecs
long curTimeInMs = beforeTime.getTime();
Date afterAddingMins = new Date(curTimeInMs + (minutes * ONE_MINUTE_IN_MILLIS));
return afterAddingMins;
}
In order to avoid any dependency you can use java.util.Calendar as follow:
Calendar now = Calendar.getInstance();
now.add(Calendar.MINUTE, 10);
Date teenMinutesFromNow = now.getTime();
In Java 8 we have new API:
LocalDateTime dateTime = LocalDateTime.now().plus(Duration.of(10, ChronoUnit.MINUTES));
Date tmfn = Date.from(dateTime.atZone(ZoneId.systemDefault()).toInstant());
This is incorrectly specified:
SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd HH:mm");
You're using minutes instead of month (MM)
tl;dr
LocalDateTime.parse(
"2016-01-23 12:34".replace( " " , "T" )
)
.atZone( ZoneId.of( "Asia/Karachi" ) )
.plusMinutes( 10 )
java.time
Use the excellent java.time classes for date-time work. These classes supplant the troublesome old date-time classes such as java.util.Date and java.util.Calendar.
ISO 8601
The java.time classes use standard ISO 8601 formats by default for parsing/generating strings of date-time values. To make your input string comply, replace the SPACE in the middle with a T.
String input = "2016-01-23 12:34" ;
String inputModified = input.replace( " " , "T" );
LocalDateTime
Parse your input string as a LocalDateTime as it lacks any info about time zone or offset-from-UTC.
LocalDateTime ldt = LocalDateTime.parse( inputModified );
Add ten minutes.
LocalDateTime ldtLater = ldt.plusMinutes( 10 );
ldt.toString(): 2016-01-23T12:34
ldtLater.toString(): 2016-01-23T12:44
See live code in IdeOne.com.
That LocalDateTime has no time zone, so it does not represent a point on the timeline. Apply a time zone to translate to an actual moment. Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland, or Asia/Karachi. Never use the 3-4 letter abbreviation such as EST or IST or PKT as they are not true time zones, not standardized, and not even unique(!).
ZonedDateTime
If you know the intended time zone for this value, apply a ZoneId to get a ZonedDateTime.
ZoneId z = ZoneId.of( "Asia/Karachi" );
ZonedDateTime zdt = ldt.atZone( z );
zdt.toString(): 2016-01-23T12:44+05:00[Asia/Karachi]
Anomalies
Think about whether to add those ten minutes before or after adding a time zone. You may get a very different result because of anomalies such as Daylight Saving Time (DST) that shift the wall-clock time.
Whether you should add the 10 minutes before or after adding the zone depends on the meaning of your business scenario and rules.
Tip: When you intend a specific moment on the timeline, always keep the time zone information. Do not lose that info, as done with your input data. Is the value 12:34 meant to be noon in Pakistan or noon in France or noon in Québec? If you meant noon in Pakistan, say so by including at least the offset-from-UTC (+05:00), and better still, the name of the time zone (Asia/Karachi).
Instant
If you want the same moment as seen through the lens of UTC, extract an Instant. The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).
Instant instant = zdt.toInstant();
Convert
Avoid the troublesome old date-time classes whenever possible. But if you must, you can convert. Call new methods added to the old classes.
java.util.Date utilDate = java.util.Date.from( instant );
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to java.time.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8 and SE 9 and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
See How to use….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
There's an error in the pattern of your SimpleDateFormat. it should be
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm");
use this format,
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm");
mm for minutes and MM for mounth
Once you have you date parsed, I use this utility function to add hours, minutes or seconds:
public class DateTimeUtils {
private static final long ONE_HOUR_IN_MS = 3600000;
private static final long ONE_MIN_IN_MS = 60000;
private static final long ONE_SEC_IN_MS = 1000;
public static Date sumTimeToDate(Date date, int hours, int mins, int secs) {
long hoursToAddInMs = hours * ONE_HOUR_IN_MS;
long minsToAddInMs = mins * ONE_MIN_IN_MS;
long secsToAddInMs = secs * ONE_SEC_IN_MS;
return new Date(date.getTime() + hoursToAddInMs + minsToAddInMs + secsToAddInMs);
}
}
Be careful when adding long periods of time, 1 day is not always 24 hours (daylight savings-type adjustments, leap seconds and so on), Calendar is recommended for that.
Can be done without the constants (like 3600000 ms is 1h)
public static Date addMinutesToDate(Date date, int minutes) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.MINUTE, minutes);
return calendar.getTime();
}
public static Date addHoursToDate(Date date, int hours) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.HOUR_OF_DAY, hours);
return calendar.getTime();
}
example of usage:
System.out.println(new Date());
System.out.println(addMinutesToDate(new Date(), 5));
Tue May 26 16:16:14 CEST 2020
Tue May 26 16:21:14 CEST 2020
Work for me DateUtils
//import
import org.apache.commons.lang.time.DateUtils
...
//Added and removed minutes to increase current range dates
Date horaInicialCorteEspecial = DateUtils.addMinutes(new Date(corteEspecial.horaInicial.getTime()),-1)
Date horaFinalCorteEspecial = DateUtils.addMinutes(new Date(corteEspecial.horaFinal.getTime()),1)
For android developers, here's a kotlin implementation using an extension of #jeznag's answer
fun Date.addMinutesToDate(minutes: Int): Date {
val minuteMillis: Long = 60000 //millisecs
val curTimeInMs: Long = this.time
val result = Date(curTimeInMs + minutes * minuteMillis)
this.time = result.time
return this
}
an unit test to check functionality works as expected
#Test
fun `test minutes are added to date`() {
//given
val date = SimpleDateFormat("dd-MM-yyyy hh:mm").parse("29-04-2021 23:00")
//when
date?.addMinutesToDate(45)
//then
val calendar = Calendar.getInstance()
calendar.time = date
assertEquals(29, calendar[Calendar.DAY_OF_MONTH])
assertEquals(23, calendar[Calendar.HOUR_OF_DAY])
assertEquals(45, calendar[Calendar.MINUTE])
}
Just for anybody who is interested. I was working on an iOS project that required similar functionality so I ended porting the answer by #jeznag to swift
private func addMinutesToDate(minutes: Int, beforeDate: NSDate) -> NSDate {
var SIXTY_SECONDS = 60
var m = (Double) (minutes * SIXTY_SECONDS)
var c = beforeDate.timeIntervalSince1970 + m
var newDate = NSDate(timeIntervalSince1970: c)
return newDate
}

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