About Calendar Systems
Gregorian Calendar
The Gregorian calendar is the calendar used in most of the world. It was introduced in October 1582 by Pope Gregory XIII as a modification of the Julian calendar to correct the drift in the date of Easter. It's a solar calendar with 12 months and 365 days, with a leap day added to February every 4 years, except for years divisible by 100 but not by 400.
Epoch: January 1, 1 AD (Anno Domini)
Current Year: 2025 AD
Julian Calendar
The Julian calendar was introduced by Julius Caesar in 45 BCE and was used in Europe until the Gregorian reform. It's still used by some Orthodox churches for religious dates. The Julian calendar has a regular year of 365 days divided into 12 months, with a leap day added to February every 4 years without exception.
Epoch: January 1, 45 BCE
Current Year: 2025 AD (same as Gregorian for this tool)
Islamic (Hijri) Calendar
A lunar calendar consisting of 12 months in a year of 354 or 355 days. It's used to determine Islamic holidays and rituals. The calendar begins with the Hijra, the migration of the Prophet Muhammad from Mecca to Medina in 622 CE. Islamic months begin at sunset of the day when the lunar crescent is first seen.
Epoch: July 16, 622 CE (Gregorian)
Current Year: 1446 AH (Anno Hegirae)
Persian (Jalali) Calendar
A solar calendar used in Iran and Afghanistan. It has 12 months and is more accurate than the Gregorian calendar for determining equinoxes. The calendar begins with the Hijra but is solar-based. The first six months have 31 days, the next five have 30 days, and the last month has 29 or 30 days in leap years.
Epoch: March 19, 622 CE (Gregorian)
Current Year: 1404 SH (Solar Hijri)
Hebrew Calendar
A lunisolar calendar used for Jewish religious observances. It has 12 or 13 months in a year, with an extra month added 7 times in a 19-year cycle to keep the calendar aligned with the solar year. Years can be 353, 354, or 355 days in common years, and 383, 384, or 385 days in leap years.
Epoch: October 7, 3761 BCE (Gregorian)
Current Year: 5785 AM (Anno Mundi)
Afghan Calendar
The official calendar of Afghanistan which is based on the solar Hijri calendar but with different month names derived from the zodiac. It's used alongside the Islamic calendar for official purposes. The months are named after the zodiac signs in Pashto, and the calendar begins on the vernal equinox (Nowruz).
Epoch: March 21, 622 CE (Gregorian)
Current Year: 1404 SH (Solar Hijri)
