Why is the month changed to 50 after I added 10 minutes?

Question

I have this date object:

SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd HH:mm");
Date d1 = df.parse(interviewList.get(37).getTime());

value of d1 is Fri Jan 07 17:40:00 PKT 2011

Now I am trying to add 10 minutes to the date above.

Calendar cal = Calendar.getInstance();
cal.setTime(d1);
cal.add(Calendar.MINUTE, 10);
String newTime = df.format(cal.getTime());

Value of newTime changes to 2011-50-07 17:50 but it should be 07-01-2011 17:50.

It adds minutes correctly but it also changes month, don't know why!

Answer 1

The issue for you is that you are using mm. You should use MM. MM is for month and mm is for minutes. Try with yyyy-MM-dd HH:mm

Other approach:

It can be as simple as this (other option is to use joda-time)

static final long ONE_MINUTE_IN_MILLIS=60000;//millisecs

Calendar date = Calendar.getInstance();
long t= date.getTimeInMillis();
Date afterAddingTenMins=new Date(t + (10 * ONE_MINUTE_IN_MILLIS));

Answer 2

you can use DateUtils class in org.apache.commons.lang3.time package

int addMinuteTime = 5;
Date targetTime = new Date(); //now
targetTime = DateUtils.addMinutes(targetTime, addMinuteTime); //add minute