Working with dates, timezones, zulu

[Anthony Smith]

Simple code...


String timestamp = "20050801042000Z+0500";
SimpleDateFormat fmtTimestamp = new SimpleDateFormat("yyyyMMddHHmmssZ");
Date deliveryDate = fmtTimestamp.parse(timestamp.replaceAll("Z", ""));
System.out.println(deliveryDate);

When I print this I get: 2005-07-31 18:20:00.0

But I am really wanting to see is this:
2005-08-01 9:20:00.0

What am I doing wrong?

[Jeff Albertson]

I think you want to produce the following, string right?

  
2005-07-31 23:20:00.0

Because that would be the GMT time for your timestamp.
Anyhowdy, the problem with your code is that Date has no
timezone state -- when you output it (implicitly using its toString()),
it formats using the timezone of your JVM.
The solution is to use a DateFormat and set its timezone to GMT:
[CODE
String timestamp = "20050801042000Z+0500";
SimpleDateFormat fmtTimestamp = new SimpleDateFormat("yyyyMMddHHmmssZ");
Date deliveryDate = fmtTimestamp.parse(timestamp.replaceAll("Z", ""));

DateFormat outputFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");
TimeZone timezone = TimeZone.getTimeZone("GMT+00:00");
outputFormat.setTimeZone(timezone);
System.out.println(outputFormat.format(deliveryDate));
[/CODE]

[Anthony Smith]

What I want to see is this: 2005-08-01 9:20:00.0

I tried the code you gave me and it gave me this: 2005-07-31 18:20:00.0

[Jeff Albertson]

Tnen I'm having trouble understanding your timestamp string:

20050801042000Z+0500

That's hour=04, minute=20, second=00, timezone=5 hours ahead of GMT, right?

That time zone make it somewhere in Pakistan, right?

[Jeff Albertson]

I want to make sure I understand how you view timezones:

20050801042000Z+0500

That's 5 hours ahead of GMT, right?

That timezone makes it somewhere in Pakistan, for example?

[Anthony Smith]

right.

[Jeff Albertson]

So if it's 4:20 in Pakistan, why do you want your result to show 9:20?
Wouldn't that be the time in Guam? Wouldn't the time at UTC/GMT be 5 hours
earlier -- 23:20?