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(Mini-) Cheat-Sheet: Date to String and String to Date in Java

It’s Java-time.

I need this from time to time, and each time I have to look it up. A little reminder for myself.

How to create a date:

Date object representing “now”:

Date date = new Date();

Date object representing a specific time using Calendar:

Calendar cal = Calendar.getInstance();
cal.set(2012, Calendar.DECEMBER, 21, 14, 21, 33);
Date date = cal.getTime();

Date object representing a specific time using SimpleDateFormat:

SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss");
Date date = sdf.parse("21/12/2012 14:21:33");

How to format a date:

Using SimpleDateFormat:

Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss");
String s = sdf.format(date);

There’s many more ways to do this, but these are just common ways.

Here is an overview of the format strings.

  Meaning Type Example
G Era designator Text AD
y Year Year 1996; 96
Y Week year Year 2009; 09
M Month in year Month July;Jul;07
w Week in year Number 27
W Week in month Number 2
D Day in year Number 189
d Day in month Number 10
F Day of week in month Number 2
E Day name in week Text Tuesday; Tue
u Day number of week (1 = Monday, …, 7 = Sunday) Number 1
a Am/pm marker Text PM
H Hour in day (0-23) Number 0
k Hour in day (1-24) Number 24
K Hour in am/pm (0-11) Number 0
h Hour in am/pm (1-12) Number 12
m Minute in Hour Number 30
s Second in minute Number 55
S Millisecond Number 978
z Time zone General time zone Pacific Standard Time; PST; GMT-08:00
Z Time zone RFC 822 time zone -0800
X Time zone ISO 8601 time zone -08; -0800; -08:00

It’s taken from here.

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