Convert dates between the Julian and Gregorian calendars. Useful for historians and anyone working with historical documents.

Provides formula and examples to convert between Julian and Gregorian Calendar dates. FORTRAN Code for conversion also given.

Find out what day of the week any date falls on. Calculate the number of days between two dates. See your birthday in different calendar systems and historical context.

May 24, 2025 · This calculator converts a date to both Julian and Gregorian day numbers. Note that the Gregorian calculation is an approximation due to historical calendar changes.

I'm going to account for the change from the Julian calendar to the Gregorian calendar later. First, I'll work out the day of the week for the Gregorian calendar in several steps.

Using formulas can be Herculean, so we would like you to use our online date converters for conversions between Julian and Gregorian dates. CalendarLabs makes determining the Julian and …

Free online tools to generate, calculate, convert, format, transform, and de/en-code. Convert between Gregorian (modern) and Julian (old style) calendar dates. The Julian calendar was introduced by …

Apr 24, 2017 · Converting a Julian date to a Gregorian date is simple arithmetic matter, once you know the formula. Pick off the millennium and century digits of the year in question. For example, for the …

Algorithm 1 provides the ordinal number for a Julian calendar date. Algorithm 2 does the same for a Gregorian date. Algorithms 3 and 5 convert between the calendars by equating their ordinal …

Simple conversions between Julian Dates and Julian/Gregorian calendar dates, supporting ancient dates (BCE)