$calendar public property (available since version 2.0.7)
The calendar to be used for date formatting. The value of this property will be directly passed to the constructor of the IntlDateFormatter class. Defaults to null, which means the Gregorian calendar will be used. You may also explicitly pass the constant \IntlDateFormatter::GREGORIAN for Gregorian calendar. To use an alternative calendar like for example the Jalali calendar, set this property to \IntlDateFormatter::TRADITIONAL. The