Discrepancy in unix date command and java simpledateformat

Question

If I am running unix command

echo 1378223625 | xargs -L 1 -I '{}' date -d "@{}" "+%d-%m-%Y-%H-%M %Z"

result is 03-09-2013-17-53 CEST

If I am running from java

public class DateExperiment {
    public static void main(String[] args) {
        DateFormat df = new SimpleDateFormat("dd-MM-yyyy-H-m z");
        System.out.println(df.format(1378223625) );
    }
}

my result is 16-01-1970-23-50 CET

unix command gives correct result but java is giving me wrong result.

Can anybody explain why am getting this discrepancy? what is the mistake?

but java is giving me wrong result. No, your expectations are wrong. — Sotirios Delimanolis
– Sotirios Delimanolis, Commented Jun 23, 2014 at 2:57
Another good example of why one should not use a count-since-epoch to handle date-time values. — Basil Bourque
– Basil Bourque, Commented Jun 23, 2014 at 5:59

Sotirios Delimanolis · Accepted Answer · 2014-06-23 02:59:49Z

3

If you use a numerical value as an argument to SimpleDateFormat#format(..), it uses the Date constructor which expects a long. That constructor

Allocates a Date object and initializes it to represent the specified number of milliseconds since the standard base time known as "the epoch", namely January 1, 1970, 00:00:00 GMT.

The value you provided represents

16-01-1970-23-50 CET

The problem here is that you have seconds, not milliseconds.

You'll want

System.out.println(df.format(1378223625000L));

answered Jun 23, 2014 at 2:59

Sotirios Delimanolis

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Elliott Frisch · Accepted Answer · 2014-06-23 03:03:20Z

2

Unix is giving you the time in seconds since epoch, Java is expecting milliseconds. I get your expected output if I multiply by 1000.

System.out.println(df.format(1378223625*1000L));

Outputs

03-09-2013-11-53 EDT

answered Jun 23, 2014 at 3:03

Elliott Frisch

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