Letter 	Date or Time Component 	Presentation 	Examples
G 	Era designator 	Text 	AD
y 	Year 	Year 	1996; 96
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 in week 	Text 	Tuesday; Tue
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

více na http://java.sun.com/j2se/1.5.0/docs/api/java/text/SimpleDateFormat.html