Datetime formatGMT 24 hour

Question

I'm trying to format a DateTime to 24 hour time but it displays the wrong time between midnight and 1 AM.

String created = Datetime.now().formatGMT('yyyy-MM-dd\'T\'kk:mm:ss.SSS\'Z\'');

shows 2017-06-02T24:55:41.319Z for 12:55 AM instead of 2017-06-02T00:55:41.319Z. Is there a way to get it to display the correct time without modifying the string?

Answer 1

Take a look at SimpleDateFormat. If you want 0 based hours use H, not k.

H   Hour in day (0-23)
k   Hour in day (1-24)
K   Hour in am/pm (0-11)
h   Hour in am/pm (1-12)

Answer 2

Change k to h in string format:

String created = Datetime.now().formatGMT('yyyy-MM-dd\'T\'HH:mm:ss.SSS\'Z\'');