SimpleDateFormat shows wrong local Time

Question

I want to store a string into a databse (SQLite) for an Android App with the current time and date. For that purpose I am using SimpleDateFormat. Unfortunately it does not show the correct time when. I tried two options.

First Option (from SimpleDateFormat with TimeZone)

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z", Locale.getDefault());
        sdf.format(new Date());

Second option (from Java SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'") gives timezone as IST)

    SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss'Z'");
    sdf2.setTimeZone(TimeZone.getTimeZone("CEST"));

In both cases the time is just wrong. It is not the local time that my laptop or phone is showing but the output time is 2 hours earlier. How can I change that? I would like to have the current time of Berlin (CEST) that is also shown on my computer. I appreciate every comment.

Why not store the current time as unix timestamp? Then convert the ms into a date string when needed. Saves some bytes and can be converted to any other timezone without much hassle. — Viatcheslav Ehrmann
Store System.currentTimeMillis(); parsed as a String. Use it along with a Calendar to display it as text again. If you'd like to know how to do this, Please comment... I'll post an answer. — Vishnu
Thanks Viatcheslav and Vishnu for your comments. I already have an entry in the database with the current time in milliseconds. This should be a second entry. The first entry (in milliseconds) is used for quering entries between two time points. As the entry in milliseconds in not 'readable' for humans, I would also like to have a second readable entry in the database — VanessaF
@VanessaF I'll post an answer now to make human-readable time from MilliSeconds.. — Vishnu
As an aside consider throwing away the long outmoded and notoriously troublesome SimpleDateFormat and friends. See if you either can use desugaring or add ThreeTenABP to your Android project, in order to use java.time, the modern Java date and time API. It is so much nicer to work with. — Ole V.V.

Arvind Kumar Avinash Arvind Kumar Avinash · Accepted Answer · 2020-09-27T14:38:01

Use Europe/Berlin instead of CEST and you will get the expected result.

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

public class Main {
    public static void main(String[] args) {
        SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z");
        sdf2.setTimeZone(TimeZone.getTimeZone("Europe/Berlin"));
        System.out.println(sdf2.format(new Date()));
    }
}

Output:

2020-09-27 18:38:04 +0200

A piece of advice:

I recommend you switch from the outdated and error-prone java.util date-time API and SimpleDateFormat to the modern java.time date-time API and the corresponding formatting API (package, java.time.format). Learn more about the modern date-time API from Trail: Date Time. If 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.

Using the modern date-time API:

import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

public class Main {
    public static void main(String[] args) {
        ZonedDateTime zdt = ZonedDateTime.now(ZoneId.of("Europe/Berlin"));

        // Default format
        System.out.println(zdt);

        // Some custom format
        System.out.println(zdt.format(DateTimeFormatter.ofPattern("EEEE dd uuuu hh:mm:ss a z")));
    }
}

Output:

2020-09-27T18:42:53.620168+02:00[Europe/Berlin]
Sunday 27 2020 06:42:53 pm CEST

The modern API will alert you whereas legacy API may failover:

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

public class Main {
    public static void main(String[] args) {
        ZonedDateTime zdt = ZonedDateTime.now(ZoneId.of("CEST"));
        // ...
    }
}

Output:

Exception in thread "main" java.time.zone.ZoneRulesException: Unknown time-zone ID: CEST
    at java.base/java.time.zone.ZoneRulesProvider.getProvider(ZoneRulesProvider.java:279)
    at java.base/java.time.zone.ZoneRulesProvider.getRules(ZoneRulesProvider.java:234)
    at java.base/java.time.ZoneRegion.ofId(ZoneRegion.java:120)
    at java.base/java.time.ZoneId.of(ZoneId.java:408)
    at java.base/java.time.ZoneId.of(ZoneId.java:356)
    at Main.main(Main.java:6)

As you can see, you get an exception in this case whereas SimpleDateFormat will give you undesirable result as shown below:

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

public class Main {
    public static void main(String[] args) {
        SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z");
        sdf2.setTimeZone(TimeZone.getTimeZone("CEST"));
        System.out.println(sdf2.format(new Date()));
    }
}

Output:

2020-09-27 16:47:45 +0000

You might be wondering what this undesirable result refers to. The answer is: when SimpleDateFormat doesn't understand a time-zone, it failovers (defaults) to GMT (same as UTC) i.e. it has ignored CEST and applied GMT in this case (not a good feature IMHO 😊).

SimpleDateFormat shows wrong local Time

3 Answers

A piece of advice:

The modern API will alert you whereas legacy API may failover:

ISO 8601

What went wrong in your code?

Question: Doesn’t java.time require Android API level 26?

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