Java Notes


The java.util.Calendar class is used to represent the date and time. The year, month, day, hour, minute, second, and milliseconds can all be set or obtained from a Calendar object. The default Calendar object has the current time in it. There are also methods for making data calculations.

Other related classes: Date, and DateFormat, ...

To get the current time

The default Calendar constructor produces an object whose fields are set to the current time for the default timezone and locale.

Calendar now = Calendar.getInstance();

Getting the value of the fields

The following field names can be used as an argument to the Calendar.get(. . .) method. In all of these examples, t is a Calendar object.

Access MethodMeaning
t.get(Calendar.YEAR) int value of the year
t.get(Calendar.MONTH) int value of the month (0-11)
t.get(Calendar.DAY_OF_MONTH) int value of the day of the month (1-31)
t.get(Calendar.DAY_OF_WEEK) int value of the day of the week (0-6)
t.get(Calendar.HOUR) int value of the hour in 12 hour notation (0-12)
t.get(Calendar.AM_PM) returns either Calendar.AM or Calendar.PM
t.get(Calendar.HOUR_OF_DAY) int value of the hour of the day in 24-hour notation (0-24)
t.get(Calendar.MINUTE) int value of the minute in the hour (0-59)
t.get(Calendar.SECOND) int value of the second within the minute (0-59).
t.get(Calendar.MILLISECOND) int value of the milliseconds within a second (0-999).


See Example - Text Clock.


Sun has never gotten the Date class right, even 10 years after the first release. Take a look at