Ok, so I've pretty much tried everything. I bet it's something really simple but I can't seem to get a hold of it.

The server sends me the time, which is epoch. However when I put this into a date object it seems to automatically pick up the time zone and it adds +3 to the server time. So if the gmt time is 00.00, it says its 03.00.

I also need to add a timezone of my own. Let's say the epoch time is 00.00 again, it should read 10.00 a开发者_如何学Pythonfter I add the timezone.

any help would be much appreciated. Thank you

"It seems to add" - I suspect you're using Date.toString() which does indeed use the local time zone. The Date object itself is effectively in UTC though. Use DateFormat to perform the conversion to a string instead, and you can specify which time zone to use. You may also need to use Calendar - it depends what you're trying to do.

(Alternatively, use Joda Time in the first place, which is a better API. It may be a little bulky for your Android project though. I wouldn't be surprised if there were a "Joda Time lite" project around somewhere for precisely this sort of thing...)

EDIT: Quick sample, although it's not entirely clear what you need...

long millis = getMillisFromServer();
Date date = new Date(millis);
DateFormat format = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
format.setTimeZone(customTimeZone);
String formatted = format.format(date);

java.time

The java.util Date-Time API and their formatting API, SimpleDateFormat are outdated and error-prone. It is recommended to stop using them completely and switch to the modern Date-Time API^*.

Also, quoted below is a notice from the home page of Joda-Time:

Note that from Java SE 8 onwards, users are asked to migrate to java.time (JSR-310) - a core part of the JDK which replaces this project.

Solution using java.time, the modern Date-Time API:

import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;

public class Main {
    public static void main(String[] args) {
        long millis = 1316391494L;

        Instant instant = Instant.ofEpochMilli(millis);
        System.out.println(instant);

        // The same instant at a specific timezone
        ZonedDateTime zdt = instant.atZone(ZoneId.of("Australia/Brisbane"));
        System.out.println(zdt);
    }
}

Output:

1970-01-16T05:39:51.494Z
1970-01-16T15:39:51.494+10:00[Australia/Brisbane]

ONLINE DEMO

Learn more about the modern Date-Time API from Trail: Date Time.

What went wrong with your code?

A java.util.Date object simply represents an instant on the timeline — a wrapper around the number of milliseconds since the UNIX epoch (January 1, 1970, 00:00:00 GMT). Since it does not hold any timezone information, its toString function applies the JVM's timezone to return a String in the format, EEE MMM dd HH:mm:ss zzz yyyy, derived from this milliseconds value. To get the String representation of the java.util.Date object in a different format and timezone, you need to use SimpleDateFormat with the desired format and the applicable timezone e.g.

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

public class Main {
    public static void main(String[] args) {
        long millis = 1316391494L;
        Date date = new Date(millis);

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX[zzzz]", Locale.ENGLISH);

        sdf.setTimeZone(TimeZone.getTimeZone("Etc/UTC"));
        String strDateUtc = sdf.format(date);
        System.out.println(strDateUtc);

        sdf.setTimeZone(TimeZone.getTimeZone("Australia/Brisbane"));
        String strDateBrisbane = sdf.format(date);
        System.out.println(strDateBrisbane);
    }
}

Output:

1970-01-16T05:39:51.494Z[Coordinated Universal Time]
1970-01-16T15:39:51.494+10:00[Australian Eastern Standard Time]

ONLINE DEMO

^{* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project.}