📅Calendar Converter

About this tool

Pick a Gregorian date or press Today. The table shows the same day in the Julian calendar and as a Julian Day Number, and in the Hebrew, Islamic Umm al-Qura and civil, Persian Solar Hijri, Chinese, Japanese imperial era, Thai Buddhist, Indian national, Ethiopian, Coptic and Minguo calendars. It uses the calendar data built into your browser.

How the world's calendars differ

Calendars count days in three main ways. Solar calendars, such as the Gregorian, Persian and Indian national calendars, follow the seasons; the Persian year starts at the March equinox. Lunar calendars follow the moon: the Islamic Hijri calendar has 12 months of 29 or 30 days, about 354 days a year, so its dates move about 11 days earlier each Gregorian year and Ramadan cycles through the seasons over 33 years. Lunisolar calendars, such as the Hebrew and Chinese calendars, use lunar months but add a leap month about seven times every 19 years to stay in step with the seasons. The Julian calendar, introduced by Julius Caesar and still used for some Orthodox church feasts, adds a leap day every four years without exception, so it is now 13 days behind the Gregorian: 12 October 2026 Gregorian is 29 September 2026 Julian. Astronomers count days continuously as the Julian Day Number, 2,461,326 for that date. Others count years from a founding era, such as Japan's Reiwa era, the Buddhist era (543 years ahead) and the Minguo calendar from 1912. Honest limits: Hebrew and Islamic days begin at sunset, and many communities start Islamic months by local moon sighting, which can differ by a day or two from the calculated calendar. This tool converts from Gregorian dates only. The day of the week calculator finds weekdays and the date difference calculator counts the days between dates.

Frequently asked questions