How Accurate Are Calendars?

[humanearth]

Over the many centuries there have been many calendars.

I have always wonder which one is the most accurate.

Here are the ones I know about and I bet there are more

Julian calendar

Gregorian calendar

Persian calendar

Revised Julian calendar

Mayan calendar

Jewish calendar

Coptic calendar

365-day calendar
(no leap years)

[NamerOfStars]

Currently, the most accurate is the Gregorian, under which it's currently March 25th, 2023 (since 2000 wasn't actually a leap year). Solar calendars have an enormous advantage over lunar ones (like the Hebrew and Hijri) because the moon changes its position relative to the Earth MUCH faster than the Earth relative to the sun, which throws off long-term accuracy. Obviously, over enough time, the Earth moves too, which is why Stonehenge doesn't work for timekeeping any more, but that takes a longer time. Eventually, even Newgrange won't work.

[humanearth]

Stonehenge was a calendar?

[NamerOfStars]

Among other things, yes.

[Pete671]

They all accurate imho, just different ways and managing the days,,,

[Msputiton]

Pretty accurate but not perfect.

Just like our days truly aren't 24hrs. They vary from 23hrs 56 minutes, to sometimes 24hrs sometimes a little more than 24hrs.

In fact leap day is a reset to fix the time so it's not off.

[TrueConfection]

Well... According to the IRS, we all know when tax day is scheduled

[exitseven]

ues I can't put it off much longer.

[TrueConfection]

Thanks for the MHO ❤

[Jaximus-Lion]

Well! Lets go down to how all started! The Sumerians that had lunar and solar calender system with a 360 days span back then and then the Persian and Eastern calender took of after with being more accurate. So from your list! Persian should be the most accurate (according science which has nothing to do with religion, according to me 😁)

[humanearth]

That list is purely from my high school memory.

But your right

[NostalgiaSenpi]

There was a proposed calendar for thirteen months, where each month would have 28 days, but also have Year Day to make the total 365 days. The extra month was to be Sol and Sol 17th would be the current Fourth of July.

https://myweb.ecu.edu/mccartyr/13-month.htm#:~:text=The%2013%2Dmonth%20calendar%20was,had%20devised%2015%20years%20before.

[slatyb]

What does "accurate" mean to you? That the average year is close to the same length as the mean solar year, meaning the seasons don't drift? Then the Gregorian calendar is the most accurate.

[Anonymous]

The simple answer is no. None of the calendar systems currently in use around the world perfectly reflect the length of a tropical year. However, there are calendar systems that are more accurate than the Gregorian calendar we use today.

[Likes2drive]

Maybe Mayan but none are completely accurate

[SnowedIn]

Very accurate, each to their own use.

[Guardian45]

If they're analog, very! 😂

[Guardian45]

https://time.is/New_York

[Guardian45]

https://clock.zone/

[humanearth]

Okay that was cool