parsing date with "yyyy-MM-dd hh:mm:ss" pattern

Question

I am facing weird behavior with "yyyy-MM-dd hh:mm:ss" date parsing pattern. below is my code.

    public static void main(String[] args) throws Exception {
        System.out.println(parseDate("2018-08-16 11:00:00"));
        System.out.println(parseDate("2018-08-16 12:00:00"));
        System.out.println(parseDate("2018-08-16 13:00:00"));
    }

    public static Date parseDate(String date) throws Exception {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        return sdf.parse(date);
    }

and I am getting following output

Thu Aug 16 11:00:00 UTC 2018

Thu Aug 16 00:00:00 UTC 2018

Thu Aug 16 13:00:00 UTC 2018

I don't understand the second output why for "2018-08-16 12:00:00" its saying Thu Aug 16 00:00:00 UTC 2018 instead of Thu Aug 16 12:00:00 UTC 2018.

looking at the docs for date parsing pattern from here. It says

h -> Hour in am/pm (1-12)

can someone please explain this? Thanks in anticipation.

Without the `am`/`pm` value, what is `12`? I'd also suggest that you should be using the new date/time introduced in Java 8 — MadProgrammer, Aug 17 '18 at 05:49
Also, if you use the `SimpleDateFormat` (and the same format) to `format` the result, it will print `2018-08-16 12:00:00` :/ - Remember, `Date#toString` has it's own internal mechanism for formatting it's representation — MadProgrammer, Aug 17 '18 at 06:04
I recommend you avoid the `SimpleDateFormat` class. It is not only long outdated, it is also notoriously troublesome. Today we have so much better in [`java.time`, the modern Java date and time API](https://docs.oracle.com/javase/tutorial/datetime/). — Ole V.V., Aug 17 '18 at 08:27
As Ole V.V. commented, the terribly troublesome old date-time classes such as [`java.util.Date`](https://docs.oracle.com/javase/10/docs/api/java/util/Date.html), [`java.util.Calendar`](https://docs.oracle.com/javase/10/docs/api/java/util/Calendar.html), and `java.text.SimpleDateFormat` are now [legacy](https://en.wikipedia.org/wiki/Legacy_system), supplanted by the [*java.time*](https://docs.oracle.com/javase/10/docs/api/java/time/package-summary.html) classes built into Java 8 and later. See [*Tutorial* by Oracle](https://docs.oracle.com/javase/tutorial/datetime/TOC.html). — Basil Bourque, Aug 17 '18 at 22:23

score 0 · Answer 1 · answered Aug 17 '18 at 06:06

Hope this helps

public static void main(String[] args) throws Exception {
    System.out.println(parseDate("2018-08-16 11:00:00 AM"));
    System.out.println(parseDate("2018-08-16 12:00:00 PM"));
    System.out.println(parseDate("2018-08-16 13:00:00 AM"));
}

public static Date parseDate(String date) throws Exception {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss a");
    return sdf.parse(date);
}

Output

Thu Aug 16 11:00:00 IST 2018 Thu Aug 16 12:00:00 IST 2018 Thu Aug 16 13:00:00 IST 2018

Rcordoval · Answer 2 · 2018-08-17T23:38:44.787

0

You should use H instead hh for Hour in day (0-23) :

TestP:

public class TestP{
    public static void main(String[] args) throws Exception {
        System.out.println(parseDate("2018-08-16 11:00:00"));
        System.out.println(parseDate("2018-08-16 12:00:00"));
        System.out.println(parseDate("2018-08-16 13:00:00"));
        System.out.println(parseDate("2018-08-16 23:00:00"));
    }

    public static Date parseDate(String date) throws Exception {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd H:mm:ss");
        return sdf.parse(date);
    }
}

Output:

Thu Aug 16 11:00:00 CLST 2018
Thu Aug 16 12:00:00 CLST 2018
Thu Aug 16 13:00:00 CLST 2018
Thu Aug 16 23:00:00 CLST 2018

Docs: SimpleDateFormat

edited Aug 17 '18 at 23:38

answered Aug 17 '18 at 06:20

Rcordoval

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`AddRotatedAnnotation`?? – Basil Bourque Aug 17 '18 at 22:22
FYI, the terribly troublesome old date-time classes such as [`java.util.Date`](https://docs.oracle.com/javase/10/docs/api/java/util/Date.html), [`java.util.Calendar`](https://docs.oracle.com/javase/10/docs/api/java/util/Calendar.html), and `java.text.SimpleDateFormat` are now [legacy](https://en.wikipedia.org/wiki/Legacy_system), supplanted by the [*java.time*](https://docs.oracle.com/javase/10/docs/api/java/time/package-summary.html) classes built into Java 8 and later. See [*Tutorial* by Oracle](https://docs.oracle.com/javase/tutorial/datetime/TOC.html). – Basil Bourque Aug 17 '18 at 22:22

score 0 · Accepted Answer · answered Aug 17 '18 at 07:23

You have change bellow line

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

to

DateFormat writeFormat = new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss");

Hours date format like below,

kk :- Hours in 1-24 format
hh :- hours in 1-12 format
KK :- hours in 0-11 format
HH :- hours in 0-23 format

parsing date with "yyyy-MM-dd hh:mm:ss" pattern

3 Answers3

TestP:

Output: