RamCal is a perpetual calendar that gives the day of the week for any given date.

It’s a universal calendar that converts dates into the following calendars : Gregorian, Julian, Julian with Roman style (kalends, nones, ides), French republican (as well as a simulation of the continuation of this calendar), Jewish and Muslim.

You just have to enter a date in one of these calendars to automatically see the conversion in the other calendars and to see the day of the week for the Julian, Gregorian and French republican calendars.