Julian Date Today 2025. The julian calendar uses a simple leap year system and is 13 days behind the gregorian calendar. To see an example, click 'show example'.

Julian dates (abbreviated jd) are simply a continuous count of days and fractions since noon universal time on january 1, 4713 bc (on the julian calendar). Unlike the gregorian calendar, which is more commonly used today, the julian calendar follows a slightly different set of leap year rules.