问题
I am working on date format with SimpleDateFormat. But when I format my date in provide format, year value increment by 1.The condition happen with that value. Why this happen?
SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-YYYY");
System.out.println("dob - "+date); // Java date
System.out.println("formatted date - "+sdf.format(date));
Output as follows :
dob - Sun Dec 28 00:00:00 IST 1975
formatted date - 28-12-1976
Year value increment by 1. Why this happen.
回答1:
As per Oracle docs
capital Y means week year,you should use yyyy in place of YYYY
change SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-YYYY"); to
SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
回答2:
You should use SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
as y means year while 'Y' means week Year.
Below are supported codes to be used in SimpleDateFormat.
Letter Date or Time Component Presentation Examples
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
回答3:
Try to use "yyyy" instead of "YYYY".
See for more info: SimpleDateFormat producing wrong date time when parsing "YYYY-MM-dd HH:mm"
- Y means "Week year"
- y means "Calendar year"
来源：https://stackoverflow.com/questions/29895133/issue-with-simpledateformat