How do I get milliseconds from epoch (1970-01-01) in Java?

Question

I need to get the number of milliseconds from 1970-01-01 UTC until now UTC in Java.

I would also like to be able to get the number of milliseconds from 1970-01-01 UTC to any other UTC date time.

@PaulG - Number one reason for downvote is *research effort*. The question is solved by a simple google. — Brian Roach, Dec 05 '12 at 19:52

score 202 · Accepted Answer · edited Dec 24 '22 at 09:04

202

From the JavaDoc:

Returns: the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC

Java 8 introduces the java.time framework, particularly the Instant class which "...models a ... point on the time-line...":

long now = Instant.now().toEpochMilli();

Returns: the number of milliseconds since the epoch of 1970-01-01T00:00:00Z -- i.e. pretty much the same as above :-)

edited Dec 24 '22 at 09:04

starball

answered Dec 05 '12 at 19:52

Anders R. Bystrup

3

As this answer was 2012 and Java 8 was not around it is a good one. Equally good is the java.time answer from Prezemek. That considers the current Java 8 java.time framework. – Zack Jannsen Feb 18 '16 at 13:03
1

For Edification: I tested a couple of ways to get a UTC time in Milliseconds and found java.time.Instant.now().toEpochMilli to work well. I compared this to ZonedDateTime.now(ZoneOffset.UTC) method options (which I have seen in other posts as options) and as expected, the Java.time.Instant.now() approach was a little faster on my machine ... low single digit milliseconds on thirty consecutive runs. – Zack Jannsen Feb 18 '16 at 13:12
Remember also that `System.currentTimeInMs()` does not update every millisecond! – Caveman Nov 15 '18 at 15:04

score 59 · Answer 2 · edited Jul 24 '16 at 15:20

59

java.time

Using the java.time framework built into Java 8 and later.

import java.time.Instant;

Instant.now().toEpochMilli(); //Long = 1450879900184
Instant.now().getEpochSecond(); //Long = 1450879900

This works in UTC because Instant.now() is really call to Clock.systemUTC().instant()

edited Jul 24 '16 at 15:20

Hack-R

answered Dec 23 '15 at 14:14

Przemek

score 17 · Answer 3 · answered Dec 05 '12 at 19:52

17

Also try System.currentTimeMillis()

answered Dec 05 '12 at 19:52

Alexander Pavlov

score -2 · Answer 4 · answered Sep 02 '19 at 15:46

-2

You can also try

  Calendar calendar = Calendar.getInstance();
  System.out.println(calendar.getTimeInMillis());

getTimeInMillis() - the current time as UTC milliseconds from the epoch

answered Sep 02 '19 at 15:46

Hari Rao

3

This terrible date-time class was supplanted years ago by the modern *java.time* classes defined by JSR 310. See modern solution in Answers by Bystrup & Hack-R – Basil Bourque Sep 02 '19 at 16:31
1

Modern solution using `java.time.Instant` seen in [this Answer](https://stackoverflow.com/a/13731260/642706) and [this Answer](https://stackoverflow.com/a/34437574/642706) – Basil Bourque Sep 02 '19 at 23:08