The Western calendar in current use is the Gregorian calendar. To convert a contemporary Western date to another calendar, use Gregorian for the contemporary Western date.

Israel obtained its independence on May 14, 1948. This finds the Jewish date:

This finds the Western date corresponding to the 50th Jewish anniversary:

Between 1582 and 1752, Catholic countries used the Gregorian calendar, while Britain and her colonies used the Julian calendar. To convert British and Catholic dates occurring between 1582 and 1752, it is necessary to change calendars from Julian to Gregorian.

George Washington was born on February 22, 1732. In France, the date was:

Voltaire was born on November 21, 1694. In Great Britain the date was:

To know the day of the week corresponding to Voltaire's birth, use the Gregorian option:

To compute the number of days Voltaire lived, use the Gregorian option:

The Russian Orthodox Church still uses the Julian calendar. This finds the Western (Gregorian) date of Greek Orthodox Christmas 2000: