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Comment by behnamoh | Hacker News Reader

As a Persian, I always found the Gregorian calendar weird. In Iran and some other countries, Jalali calendar is used which is much more straightforward:

https://en.wikipedia.org/wiki/Jalali_calendar

   The Iranian calendar (also known as Persian calendar or the Jalaali Calendar) 
   is a solar calendar currently used in Iran and Afghanistan. It is 
   observation-based, rather than rule-based, beginning each year on the vernal 
   equinox as precisely determined by astronomical observations from Tehran.

There are 12 months. The first 6 have 31 days and the rest have 30 days, except the last month which is 29 days. Every 4 years, it's a leap year and the last month becomes also 30 days.

It's also precisely set to follow seasons. For example, the first day of Fall is actually the first day of "Mehr" (the 7th month). For some reason, the Gregorian calendar has it on Sep. 22.

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> For example, the first day of Fall is actually the first day of "Mehr" (the 7th month). For some reason, the Gregorian calendar has it on Sep. 22.

That’s just a convention. In Russia we use “meteorological” convention, for example, and so each season starts on the 1st of some month (March, June, September, December). It is off from the astronomical convention by ≈20 days and it is off from reality by whatever depending on your location and your feelings on what constitutes seasons.

The Julian calendar, which the Gregorian is a revision of, was designed precisely so that societies didn't need a public servant dedicated to keeping the calendar up to date.

>For example, the first day of Fall is actually the first day of "Mehr" (the 7th month). For some reason, the Gregorian calendar has it on Sep. 22.

The particular locations of the equinoxes and solstices on the calendar isn't as important as keeping them more or less in the same places as time goes on.

Yes. My partner is Iranian and their birthday is out of sync (earlier) every leap year. We “discovered” that the one first year it happen to us when suddenly received birthday wishes by all their Iranian network the day “before” the Gregorian calendar birthday.

For what it's worth many early European cultures also considered the start of the year to be at the start of spring, generally the same idea as Nowruz, which is where we got Easter from as a conglomeration of "pagan" rituals and Christian religion. Unfortunately we ended up with this weird Dec. 31st at the end of a year in the middle of winter which doesn't make any logical sense.

There’s more similarities than just that. Iran was founded by Indo-Europeans.

Many similarities in languages too. Persian (Farsi) has the same root as some European languages (and should not be confused with Arabic, which is totally different than both).

    In Persian | In English
    mädar      | mother
    barädar    | brother
    dokhtar    | daughter
    pedar      | father
    bad        | bad
    ...

I’m familiar. It is fascinating. Same with Sanskrit. I don’t know if we’re all descended from the same people exactly, or if the Indo Europeans were just an extremely successful core group with a culture that all of us adopted as the natives wherever they spread to. But they certainly had a successful culture. Iran should really be an ally with the western democracies. Those people are actually pretty advanced and modern, considering where they are placed in the world.

I say that to my American and European friends, that Iranians have a lot more in common with them than with the rest of the middle east. There are exceptions, of course, but the general public is really well educated, open minded, and leaning towards Western values and culture.

Too bad that the country has received such a negative reputation over the past 4 decades due to its (non-Iranian) regime.

I’m American and that’s my perspective. I can’t be the only one. I never even understood why Iran and the US were at odds. Seems entirely based on politics/elites. From what I see, Iranians would be my first pick as allies in the region. We certainly chose poorly with Saudi Arabia.

Non-Western values and culture are a great portion of why we need Iran. A shelter from and an antidote to global liberal hegemony.

> It's also precisely set to follow seasons. For example, the first day of Fall is actually the first day of "Mehr" (the 7th month). For some reason, the Gregorian calendar has it on Sep. 22.

This doesn't really work; the first day of Fall differs from place to place according to the specifics of the local climate.

https://en.wikipedia.org/wiki/Equinox

Why would that be considered the first day of Fall? Even taking a purely astronomical perspective, the autumnal equinox would be the center of Fall, not the beginning.

As a not-at-all neutral observation, you post an enormous amount, are obnoxious in your confidence, and frequently wrong.

This seems a bit mean, especially given its a pretty natural question as to why the equinox is considered start of fall instead of midautumn (in certain regions)

Edit: i take it back.

Because https://en.wikipedia.org/wiki/Seasonal_lag

Yes, from a seasonal perspective, the timing of a season varies idiosyncratically from place to place. That was the first thing I said. Why would you then want to locate the beginning of Fall on the equinox?

Quoting from your link:

> seasonal lag is not "seasonally symmetric"; that is, the period between the winter solstice and thermal midwinter (coldest time) is not the same as between the summer solstice and thermal midsummer (hottest time).

> In mid-latitude continental climates, [seasonal lag] is approximately 20–25 days in winter and 25–35 days in summer.

> there is no meteorological reason for designating these dates as the first days of their respective seasons.

You asked why it is traditionally known as that, and i answered.

Not only did I not ask that, I don't believe that the equinox is traditionally known as the beginning of autumn. Traditional terminology always marks the solstices and equinoxes as the middle of the season in which they occur, because that is obviously the way seasons work. Compare Western European "Midsummer" [the solstice] or Chinese 立秋 ["beginning of Fall", August 8; compare to the equinox on September 23, or to the "Mid-Autumn Festival" 中秋节, fixed to the full moon, but generally around late September].

The equinoxes and the solstices are marked on modern calendars as the beginning of their respective seasons, but I have never heard anyone attempt to justify that. I tend to assume it's the result of the calendar-buying population not having any reason to care what season it currently is.

But even among modern calendar-buying people, I believe they think of big snowdrifts as something that happens in winter, not something that happens in late fall and continues through winter. And the calendar doesn't agree with that.

So is it astronomical season or weather season? Weather varies between locations.

Spring and autumn start on the equinox, summer and winter on the solstices. Though it's true they tend to be called "mid summer" and "mid winter" day. It's certainly weird.

We also tend to associate summer with days getting longer and winter with days (the period between sunrise and sunset) getting shorter, but the opposite is true: in summer, which is the period from about 21 June to 23 September, days are getting shorter, whereas in winter, between 21 December and 21 March, days are getting longer. Astronomical winter starts on the shortest day, and astronomical summer on the longest day.

I guess we're just eternally confused about calendars. And who can blame us?

> Astronomical winter starts on the shortest day, and astronomical summer on the longest day.

This is a convention used only by modern calendars. Astronomers have no opinion on when particular seasons occur. They care about things like when stars rise above or sink below the horizon. But they don't use the change in the sky to determine when winter occurs. People notice that winter occurs around the same time every year, and they associate whatever the sky is doing at that time with the beginning of winter.

As you already note, the solstices are called "midsummer" and "midwinter". That is because they are traditionally identified as the middle of summer and the middle of winter. Why do you believe that they are the beginning instead?

"Believe"? It's the common definition. Belief has nothing to do with it.

That doesn't come close to being true. Compare the Cambridge dictionary's "common definition":

> [summer] the season of the year between spring and autumn when the weather is warmest, lasting from June to September north of the equator and from December to March south of the equator

Wikipedia:

> Summer is the hottest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, the earliest sunrise and latest sunset occurs, daylight hours are longest and dark hours are shortest, with day length decreasing as the season progresses after the solstice. The date of the beginning of summer varies according to climate, tradition, and culture.

> From an astronomical view, the equinoxes and solstices would be the middle of the respective seasons, but sometimes astronomical summer is defined as starting at the solstice, the time of maximal insolation, often identified with the 21st day of June or December. By solar reckoning, summer instead starts on May Day and the summer solstice is Midsummer.

It "doesn't come close to being true", so you post stuff that confirms what I said?

Only your last sentence presents an alternate definition, the rest confirms it or is close to it. And the astronomical definition is not an uncommon one.

I think you need to reread what I wrote and what you wrote.

Technically days get longer (hours of daylight) during the winter and shorter during the summer.

Bruh.

You can't really define seasons with day-precision based on weather or climate.

You can't define seasons with day precision based on anything.

1/4 of the time it takes for earth to cross a line between the sun and a particular feature of the CMB, granted the CMB feature would be arbitrary

That would not match anyone's idea of what a season was. For example, it makes it impossible to say "as you go farther north, the winter gets longer and the summer gets shorter".

That actually works pretty well and has worked well for thousands of years for what it was designed to do. The calendar should not necessarily follow the local climate of every region, as that can vary each year and throughout the time. They had to fix a reference point for seasons, and they have chosen the Equinox. This is a sensible reference point (see refs). But also it could be anything else as long as it's measurable and verifiable independently and does not change based on location.

The same works for the clocks. People in Sweden still use the same 24-hour clock, even though they have vastly different daylight conditions in different seasons.

The Persian calendar is actually our most precise [1] calendars to date, and it owes its precision to tying the calendar to astronomical seasons [2].

[1] https://www.timeanddate.com/date/perfect-calendar.html [2] https://www.timeanddate.com/calendar/persian-calendar.html

Calendar seasons are mainly used to talk about the weather. Using Equinox as a fixed reference point is not any more precise than using meteorological convention wrt thermal seasons.

Here is what Equinox means and how it's related to weather in general https://www.weather.gov/lmk/seasons

> Using Equinox as a fixed reference point and a is not any more precise than using meteorological convention wrt thermal seasons

Well, no. What meteorological convention? That's a pretty broad term. We are talking about calendars, not a general weather forecast system, as I was comparing Persian calendar with other calendars.

With Equinox, you get a good indication of weather conditions for a wide geography while having a precise reference point to design a calendar which can be used for other equally important purposes.

P.S. While I was thinking about what you wrote, I wondered how these things were argued and arranged in ancient times and what did they think or say considering what they had to come up with affects a significant portion of the civilized world and trade between nations.

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