What's the most accurate calendar?

The Gregorian, Persian, Hebrew, Hindu, Mayan, etc and etc.

Which calendar is physically accurate and it goes with harmony with our solar system and universe?

8 Answers

  • 9 years ago
    Best Answer

    It depends on what you mean by "accurate". You need a standard to compare the calendars to.

    The Gregorian calendar tries to keep the spring equinox at March 21 (+/- a day or two). It uses fixed rules, and is accurate to about 1 day in 2000 years.

    The Persian (Solar Hejri) calendar is a observational calendar. It does not use fixed rules like most other calendars. In that sense, it is most "accurate". But it requires consulting an astronomical almanac, and it is impossible to say how long the year will be for more than 1000 years in advance. And maybe even less than that, whenever the vernal equinox happens close to noon. (What would happen if one person said the equinox happened 0.1 second before noon, and another person said it was 0.1 second after noon?) So the Persian calendar is no more accurate than our predictions of the orbit, inclination, and rotation of the Earth. And those predictions are basically good to only +/- 1 second for the next 25 years (especially for Earth rotation).

    The Hebrew calendar doesn't even try to match the solar cycle. It it 100% accurate in following it's own rules, which is all it tries to do. There has been some discussion about a need to change the rules, sometime in the next 5000 years or so.

    There are many Hindu calendars, so I don't know which one you might mean. Most all the variations are observational calendars, so they are 100% accurate as far as people can see the sun and moon (or use almanacs). But again, they have the problem of the equinox happening very near a time point -- in this case, sunrise.

    The Mayan calendar used 365 days a year, every year. The pre-Colombian Mayans knew this was not accurate in tracking the seasons, but they used it anyway.

    The most accurate calendar in all senses is the Julian Day (JD) calendar. It is just a count of the days since January 1, 4713 BC Greenwich noon. Today (November 13) is JD 2,455,513. This calendar is used by the astronomical community.

    • tom2 years agoReport

      Of course the Persian calnder is the most accurate calndar in the world.
      And also you must know that is the third calender of iranians and second was gregorian that gives its place to persian 1000 years ago.
      So the gregorian calendar isn't more accurate than persian

  • Anonymous
    4 years ago

    The Persian calendar or as it is called SOLAR HIJRI calendar is the most accurate calendar in the world. Its calculations come from Jalali calendar (calendar of iran 800 years ago) that has only 1 second in every 100000 years.

    • Mahdi4 years agoReport


  • 6 years ago

    Iranian (Persian) calendar that calls (Jalali or Shamsi) is the the most accurate calendar in the world.

    The Iranian calendars (Persian: گاه‌شماری ایرانی‎ Gâhshomâriye Irâni) are a succession of calendars invented or used for over two millennia in Iran (Persia). One of the longest chronological records in human history, the Iranian calendar has been modified time and again during its history to suit administrative, climatic, and religious purposes.

    The modern Iranian calendar is now the official calendar in Iran and Afghanistan. It begins on the vernal equinox as determined by astronomical calculations for the Iran Standard Time meridian (52.5°E or GMT+3.5h). This determination of starting moment is more accurate than the Gregorian calendar as far as predicting the date of the vernal equinox is concerned because it uses mathematical rules Its years are designated AP, short for Anno Persico. The Iranian year usually begins within a day of 21 March of the Gregorian calendar. To find the corresponding year of the Gregorian calendar, add 621 or 622 (depending on the time of the year) to a Solar year. A short table of year correspondences between the Persian and Gregorian calendars is provided below.



    • 5 years agoReport

      This is wrong!Only Jalali Calendar which has been used in Iran since 11th century AD is the most accurate calendar system.Old Persian or Yazdgerdi Calendars are not as accurate as Jalali Calendar.

  • Anonymous
    5 years ago

    Jalali Calendar or Shamsi Calendar (Solar Hijri)

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  • 9 years ago

    persian calendar is the most accurate calendar in the world .

    It is based on solar system

  • 4 years ago


  • 3 years ago

    Great point, I'd like to know more as well

  • Anonymous
    3 years ago

    This is an interesting question, and one that has intrigued me for a very long time.

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