Receive days starting from an era
I want the number of days since the epoch (1970-01-01). I tried with joda-time
try {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date date1 = sdf.parse("2013-05-03 07:00:00");
Date date2 = sdf.parse("2013-05-03 23:30:00");
MutableDateTime epoch = new MutableDateTime();
epoch.setDate(0); //Set to Epoch time
System.out.println("Epoch: " + epoch);
Days days1 = Days.daysBetween(epoch, new MutableDateTime(date1.getTime()));
Days days2 = Days.daysBetween(epoch, new MutableDateTime(date2.getTime()));
System.out.println("1) Days Since Epoch: " + days1.getDays());
System.out.println("2) Days Since Epoch: " + days2.getDays());
} catch (ParseException e) {
e.printStackTrace();
}
and using logic:
// Create Calendar instance
Calendar calendar1 = Calendar.getInstance();
Calendar calendar2 = Calendar.getInstance();
calendar2.setTime(date);
// Set the values for the calendar fields YEAR, MONTH, and DAY_OF_MONTH.
//calendar1.set(calendar1.YEAR, calendar1.MONTH, Calendar.DAY_OF_MONTH); calendar1.set (1970, 1, 1);
/*
* Use getTimeInMillis() method to get the Calendar time value in
* milliseconds. This method returns the current time as UTC
* milliseconds from the epoch
*/
long miliSecondForDate1 = calendar1.getTimeInMillis();
long miliSecondForDate2 = calendar2.getTimeInMillis();
// Calculate the difference in millisecond between two dates
long diffInMilis = miliSecondForDate2 - miliSecondForDate1;
/*
* Now we have difference between two date in form of millsecond we can
* easily convert it Minute / Hour / Days by dividing the difference
* with appropriate value. 1 Second : 1000 milisecond 1 Hour : 60 * 1000
* millisecond 1 Day : 24 * 60 * 1000 milisecond
*/
long diffInSecond = diffInMilis / 1000;
long diffInMinute = diffInMilis / (60 * 1000);
long diffInHour = diffInMilis / (60 * 60 * 1000);
long diffInDays = diffInMilis / (24 * 60 * 60 * 1000);
if(logger.isInfoEnabled()) {
logger.info("Difference in Seconds : " + diffInSecond);
logger.info("Difference in Minute : " + diffInMinute);
logger.info("Difference in Hours : " + diffInHour);
logger.info("Difference in Days : " + diffInDays);
}
I am getting diff output for both. can anyone help where i am wrong.
thank.
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The difference between 17006 and 17007 is one day. This difference most likely starts at 7:00 and 23:30 in your time zone on different days in a different time zone, say UTC. Or vice versa, those times in UTC happen on different days in your time zone. Therefore, the counter is disabled by one. I do not know JodaTime, so I cannot give you the exact details.
The difference between 16975 and 17006 is 31 days or a full month. I can tell exactly where it came from. Calendar
months are 0-based: January is month 0, February is 1, etc. This calendar1.set(1970, 1, 1)
sets your calendar to February 1, 1970, 31 days after the epoch. Use instead calendar1.set(1970, Calendar.JANUARY, 1)
. You will also want to control the hours, minutes and seconds Calendar
. You can call clear()
before set()
to make sure the time is at midnight.
If you can use Java 8, you can:
DateTimeFormatter format = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss");
OffsetDateTime t1 = LocalDateTime.parse("2013-05-03 07:00:00", format)
.atOffset(ZoneOffset.UTC);
OffsetDateTime t2 = LocalDateTime.parse("2013-05-03 23:30:00", format)
.atOffset(ZoneOffset.UTC);
System.out.println("1) Days Since Epoch: " + ChronoUnit.DAYS.between(Instant.EPOCH, t1));
System.out.println("2) Days Since Epoch: " + ChronoUnit.DAYS.between(Instant.EPOCH, t2));
Prints:
1) Days Since Epoch: 15828 2) Days Since Epoch: 15828
If you want to use a different time zone:
DateTimeFormatter format = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss");
ZonedDateTime t1 = LocalDateTime.parse("2013-05-03 07:00:00", format)
.atZone(ZoneId.systemDefault());
ZonedDateTime t2 = LocalDateTime.parse("2013-05-03 23:30:00", format)
.atZone(ZoneId.systemDefault());
System.out.println("1) Days Since Epoch: " + ChronoUnit.DAYS.between(Instant.EPOCH, t1));
System.out.println("2) Days Since Epoch: " + ChronoUnit.DAYS.between(Instant.EPOCH, t2));
You can fill in your desired time zone instead ZoneId.systemDefault()
.
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