Calendrical Calculations

Reingold calendars

History calendars

List of calendars

Explanatory supplement

Common Era

Gregorian calendar

Proleptic Gregorian calendar

Julian calendar

Proleptic Julian calendar

On the use of Julian dates

Julian day Calculation

Julian date

Rata Die (DN)

Modified Julian Date

Ordinal date

Islamic calendar

ISO week date

Iso calendar

Python datetime src

Python datetime api

ke!san Online Calculator

Calendar Converter for Near East Historians

Calendar Converter