Java Notes
java.util.Calendar
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 Method | Meaning |
|---|---|
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). |
Example
See Example - Text Clock.References
Sun has never gotten the Date class right, even 10 years after the first release. Take a look at weblogs.java.net/blog/mister__m/archive/2006/02/tiger_and_dates.html.