How to convert a String to a Date using SimpleDateFormat?

Question

I have this code snippet:

DateFormat formatter1;
formatter1 = new SimpleDateFormat("mm/DD/yyyy");
System.out.println((Date)formatter1.parse("08/16/2011"));

When I run this, I get this as the output:

Sun Jan 16 00:10:00 IST 2011

I expected:

Tue Aug 16 "Whatever Time" IST 2011

I mean to say I am not getting the month as expected. What is the mistake?

Answer 1

Try this:

new SimpleDateFormat("MM/dd/yyyy")

• MM is "month" (not mm)
• dd is "day" (not DD)

It's all in the javadoc for SimpleDateFormat

FYI, the reason your format is still a valid date format is that:

• mm is "minutes"
• DD is "day in year"

Also, you don't need the cast to Date... it already is a Date (or it explodes):

public static void main(String[] args) throws ParseException {
    System.out.println(new SimpleDateFormat("MM/dd/yyyy").parse("08/16/2011"));
}

Output:

Tue Aug 16 00:00:00 EST 2011

Voila!

Answer 2

m - min M - Months

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