The Gregorian calendar dominates global commerce, but billions of people use other calendar systems daily for religious, agricultural, and cultural events. Here is how they work.
The three main types
| Type | How it works | Examples |
|---|---|---|
| Solar | Tied to Earth's orbit around the Sun (365.24 days/year) | Gregorian, Julian, Persian, Indian Saka, Ethiopian |
| Lunar | Tied to lunar cycles (~29.53 days/month, ~354 days/year) | Hijri (Islamic) |
| Lunisolar | Lunar months + occasional leap month to stay in sync with sun | Hebrew, Chinese, Hindu, Buddhist |
Gregorian calendar
- Used by: Most of the world for civil purposes
- Adopted: 1582 in Catholic Europe; gradually elsewhere (UK 1752, Russia 1918, Turkey 1926, Saudi Arabia 2016 for non-religious uses)
- Year length: 365 days (366 in leap years every 4 years, except century years not divisible by 400)
- Year zero: Year 1 AD/CE is the conventional starting year (no year 0)
Hijri (Islamic) calendar
- Used by: Religious observances worldwide; civilly in Saudi Arabia, Iran (alongside Persian)
- Year 1 AH: 622 CE — the year of Prophet Muhammad's migration (hijrah) from Mecca to Medina
- Year length: 354 days (lunar year, shorter than solar)
- Months: 12 lunar months, each ~29 or 30 days
- Notable: Drifts ~11 days earlier each Gregorian year. Ramadan can fall in any season over a 33-year cycle.
- Variants: Umm al-Qura (Saudi calculation), local sighting calendars
In Hijri terms, 2026 CE corresponds roughly to 1447-1448 AH.
Hebrew calendar
- Used by: Religious observances; civil calendar in Israel (alongside Gregorian)
- Year 1: 3761 BCE — traditional Creation date
- Year length: 12 or 13 lunar months (~354 or 384 days)
- Leap year: A 13th month (Adar II) added 7 times in every 19-year cycle
- Notable: Day begins at sunset (not midnight). Sabbath is from Friday sunset to Saturday sunset.
Gregorian 2026 corresponds to 5786-5787 in the Hebrew calendar.
Buddhist Era (BE)
- Used by: Thailand, Cambodia, Laos, Sri Lanka, Myanmar (for civil documents)
- Year 1 BE: Year of Buddha's parinirvana
- Length: 543 years ahead of CE in Thailand/Cambodia/Laos
- Sri Lanka/Myanmar: 544 ahead
- Calendar: Mostly follows the Gregorian solar calendar; just the year number differs
Gregorian 2026 = Buddhist Era 2569 (Thailand)
Chinese calendar
- Used by: Traditional festivals across East Asia, religious/cultural events
- Type: Lunisolar — months tied to moon, year tied to sun
- Leap month: A 13th month is added 7 times every 19 years
- Year length: 353-385 days
- Zodiac: 12-year animal cycle (Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig)
- Element cycle: 60-year cycle combining 12 animals with 5 elements (Wood, Fire, Earth, Metal, Water)
2026 is the Year of the Horse (Fire element).
Persian (Solar Hijri) calendar
- Used by: Iran, Afghanistan (civil)
- Year 1: 622 CE (same start as Hijri but solar-based)
- Year length: 365 or 366 days (solar)
- Start of year: Spring equinox (Nowruz, March 20-21)
- Notable: Considered one of the most astronomically accurate calendars (more accurate than Gregorian)
Gregorian 2026 = Persian year 1404-1405
Indian (Saka) calendar
- Used by: Indian government as the national calendar alongside Gregorian
- Year 1 Saka Era: 78 CE
- Year length: Solar (365 days)
- Start: Around March 21-22 (spring)
Gregorian 2026 = Saka 1948
Ethiopian calendar
- Used by: Ethiopia, Eritrea, Eritrean diaspora
- Year: ~7-8 years behind Gregorian (offset by Anno Mundi count)
- Months: 12 months of 30 days each + a 13th month of 5-6 days
- New Year: September 11 or 12
Gregorian 2026 = Ethiopian year 2018-2019
Why this matters
- Religious observances: Eid, Diwali, Lunar New Year, Easter — all use non-Gregorian calculations
- Business contracts: International contracts often specify Gregorian
- Long-form scheduling: Knowing different calendars helps when planning events for multicultural communities
- Cultural literacy: Understanding why your colleague says "1448 AH" or "Saka 1948"
See more
- Hijri calendar countries — Saudi Arabia uses Islamic primary
- Persian calendar in Iran
- Buddhist calendar in Thailand
- Hebrew calendar in Israel
caldays.com supports Gregorian, Hijri (Umm al-Qura), Hebrew, Buddhist, Japanese, Chinese, Indian (Saka), Persian, Ethiopian, and Coptic calendar systems via Intl.DateTimeFormat.