Julian Day Calculator
Calculate the Julian Day Number for any calendar date
About This Tool
The Julian Day Calculator converts between calendar dates and Julian day numbers, a continuous count of days since the beginning of the Julian Period used extensively in astronomy.
Enter a date or Julian day number to convert. The tool supports both Gregorian and Julian calendars, providing accurate conversions for historical and astronomical purposes.
Useful for astronomers, historians, and researchers needing precise dating systems. No registration needed; all calculations are performed locally on your device.