International & Historical Calendar Converters
Astronomical and cultural calendar conversion utilities. Transform civil Gregorian dates to Ethiopian, Hebrew, Solar Hijri, Japanese Imperial, and Julian Day numbers.
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Ethiopian Calendar Converter
Convert modern Gregorian dates to the traditional 13-month Ethiopian calendar and Ge'ez year.
Julian Date Converter
Calculate astronomical Julian Day Numbers (JDN) and ordinal day-of-year codes for engineering.
Afghan Calendar Converter
Translate Gregorian calendar dates to the Afghan Solar Hijri (Hijri Shamsi) calendar system.
Persian / Shamsi Converter
Convert between standard Gregorian dates and the Iranian Jalali Solar Hijri calendar.
Hebrew Date Converter
Convert standard dates to Hebrew lunisolar calendar dates, tracking Jewish holidays and sunsets.
Japanese Era Converter
Convert Western years into official Japanese Imperial eras (Reiwa, Heisei, Showa, Taisho, Meiji).
Exploring Global & Historical Calendars
While the Gregorian calendar serves as the international civil standard, numerous nations, cultures, and scientific disciplines maintain specialized calendar systems. From the 13-month Ethiopian calendar and the lunisolar Hebrew calendar to Persian and Afghan Solar Hijri eras, each embodies centuries of astronomical observation.
In astronomy and historical archives, Julian Day numbers provide continuous counts of days since 4713 BC, while Japanese civil life utilizes Imperial Era (Gengō) designations. Our conversion suite calculates these complex transitions accurately.
Frequently Asked Questions
Why do different cultures use distinct calendar epochs?
Calendar epochs originate from pivotal historical, astronomical, and religious milestones—such as the Vernal Equinox in Solar Hijri or Imperial accessions in Japan.
How are leap years calculated in Solar Hijri calendars?
Solar Hijri leap years are calculated astronomically based on the exact timing of the March equinox at the Tehran/Kabul meridian.