Calendar.Builder is used for creating a Calendar from various date-time parameters.

There are two ways to set a Calendar to a date-time value. One is to set the instant parameter to a millisecond offset from the Epoch. The other is to set individual field parameters, such as YEAR, to their desired values. These two ways can't be mixed. Trying to set both the instant and individual fields will cause an IllegalStateException to be thrown. However, it is permitted to override previous values of the instant or field parameters.

If no enough field parameters are given for determining date and/or time, calendar specific default values are used when building a Calendar. For example, if the YEAR value isn't given for the Gregorian calendar, 1970 will be used. If there are any conflicts among field parameters, the resolution rules are applied. Therefore, the order of field setting matters.

In addition to the date-time parameters, the locale, time zone, week definition, and leniency mode parameters can be set.

Examples

The following are sample usages. Sample code assumes that the Calendar constants are statically imported.

The following code produces a Calendar with date 2012-12-31 (Gregorian) because Monday is the first day of a week with the ISO 8601 compatible week parameters.

   Calendar cal = new Calendar.Builder().setCalendarType("iso8601")
                        .setWeekDate(2013, 1, MONDAY).build();

The following code produces a Japanese Calendar with date 1989-01-08 (Gregorian), assuming that the default ERA is Heisei that started on that day.

   Calendar cal = new Calendar.Builder().setCalendarType("japanese")
                        .setFields(YEAR, 1, DAY_OF_YEAR, 1).build();

Since: 1.8