CODEWITHSUNDEEP
javatimejodatime
Vishal Zanzrukia
Vishal Zanzrukia

Reputation: 4973

Found weird behavior with Joda API

I started looking at joda API for handling timezone related issues for my web application. I found very weird behavior while doing so. I hope there must be some workaround. here is my snap-code.

DateTime utcDateTime = new DateTime(System.currentTimeMillis(), DateTimeZone.UTC);
DateTime currentDateTime = DateTime.now();
int seconds = Seconds.secondsBetween(utcDateTime.toLocalDateTime(), currentDateTime.toLocalDateTime()).getSeconds();
System.out.println("hours::" + (((float)seconds)/(60*60)));

My local timezone is : kolkata, India (GMT + 5:30)
then I should get 5.5 as myn console output, but I am getting hours::5.499722
Don't know Why? Am I doing anything wrong?

Upvotes: 0

Views: 70

Answers (2)

njzk2
njzk2

Reputation: 39403

(5.5 hours - 5.499722 hours) in ms
=
1000.8 ms

1 second, to the rounding/floating point precision. You call

DateTime utcDateTime = new DateTime(System.currentTimeMillis(), DateTimeZone.UTC);
DateTime currentDateTime = DateTime.now();

Seconds.secondsBetween().getSeconds() gives you an integer number of seconds. Your calls are successive meaning they can be off by even 1 millisecond, which can be rounded to 1 second when converted to int.

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1503839

Given that you want hours and minutes (an Hours object can only hold an integer number of hours) you probably want:

Period period = new Period(utcDateTime.toLocalDateTime(), 
                           currentDateTime.toLocalDateTime(),
                           PeriodType.time());

Or alternatively, and more cleanly IMO:

int offsetMillis = DateTimeZone.getDefault().getOffset(Instant.now());
Duration offset = Duration.millis(offsetMillis);

You should very rarely need to know the offset in this fashion though, in my experience.

Upvotes: 1

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