Get Time in London

java datetime calendar dst
dogbane picture dogbane · Mar 29, 2010 · Viewed 16.4k times · Source

How can I get the current local wall clock time (in number of millis since 1 Jan 1970) in London? Since my application can run on a server in any location, I think I need to use a TimeZone of "Europe/London". I also need to take Daylight Savings into account i.e. the application should add an hour during the "summer".

I would prefer to use the standard java.util libraries.

Is this correct?

TimeZone tz = TimeZone.getTimeZone("Europe/London") ;
Calendar cal = Calendar.getInstance(tz);
return cal.getTime().getTime() + tz.getDSTSavings();

Thanks

Answer

erickson picture erickson · Mar 29, 2010

I'm not sure what this quantity represents, since the "number of millis since 1 Jan 1970" doesn't vary based on location or daylight saving. But, perhaps this calculation is useful to you:

TimeZone london = TimeZone.getTimeZone("Europe/London");
long now = System.currentTimeMillis();
return now + london.getOffset(now);

Most applications are better served using either UTC time or local time; this is really neither. You can get the UTC time and time in a particular zone like this:

Instant now = Instant.now(); /* UTC time */
ZonedDateTime local = now.atZone(ZoneId.of("Europe/London"));

Related questions

Converting local time to UTC time or vice versa considering daylight saving time

I know how to convert local time to UTC time and vice versa. But I am very much confused about daylight savings time(DST) handling while doing this. So can anyone answer the below questions: 1. Does java internally handle DST …

Read More
Convert String to Calendar Object in Java

I am new to Java, usually work with PHP. I am trying to convert this string: Mon Mar 14 16:02:37 GMT 2011 Into a Calendar Object so that I can easily pull the Year and Month like this: String yearAndMonth = cal.get(Calendar.…

Read More
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?

Read More