Assume currently the date is the 28th of May. If I call the following commands in order the output becomes

cal.add(Calendar.DATE, 1);  // Day = 29
cal.add(Calendar.DATE, 1);  // Day = 30
cal.add(Calendar.DATE, 1);  // Day = 31
cal.add(Calendar.DATE, 1);  // Day = 31
cal.add(Calendar.DATE, -1); // Day = 29

Why is this not jumping into the next month? And why is it stuck at the 31st (but when you minus one it jumps to 29)?

java android calendar
Edit
Report