Calendar Converter

Select a date using the Gregorian calendar as reference. The tool will instantly show the equivalent date in 11 other calendar systems below. Each card displays the calendar name, the converted date, and the era used for year counting. The Julian Day number is a continuous count of days used in astronomy — it is the same regardless of which calendar you are looking at. The moon phase is calculated from the synodic month and may differ from the actual phase by up to 1.5 days.