I only watched the Game of Thrones TV series. But there it was said that the current summer lasted for already nine years. In our world a "year" is the time in which all four seasons pass. Since this is different in Westeros, they seem to have some other way of saying what a "year" is. Is this somehow explained in the books?

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    Point of order: An Earth year is in fact the period of time it takes for Earth to complete a revolution around the sun. That we complete all 4 seasons during that time is not a part of the definition.
    – user1027
    Commented Aug 1, 2011 at 16:34
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    @Keen: True. But originally, when our ancestors did not know revolutions around the sun, a year was the passing of four seasons.
    – Till B
    Commented Aug 1, 2011 at 17:31
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    possible duplicate of Explanation of seasons in "A Song of Ice and Fire"
    – apoorv020
    Commented Aug 1, 2011 at 17:44
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    @Till B: depends on your ancestors. The 4 seasons are only present in the northern and southern regions, where as the tropical areas do not having any proper seasons. Commented Jan 18, 2013 at 1:51
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    @TillB: Not so. A year was measured by changes in the position of the sun and the length of the days. It was useful because of the changing of the seasons (which is why equatorial cultures tend to use lunar calendars instead) but it was never measured by them. How would you? There's no clear point to define as the end of winter, for example. Commented Feb 14, 2013 at 11:43

14 Answers 14


It appears that a Year is measured the same way as it currently is for us, approximately 365 rotations of the planet or one trip around the sun. I have not found this stated explicitly though.

As for the changing of seasons I found the post below.

From "Westeros", A Wiki of Ice and Fire

Westeros is at the mercy of erratic seasons that may last for many years, but whose duration is unpredictable. At the beginning of A Song of Ice and Fire the continent has enjoyed a decade-long summer, and many fear that an equally long and harsh winter will follow. It is unclear to which degree the eastern continent is subject to the same conditions. George R. R. Martin explicitly and more than once stated that the explanation of the Planet's climate will be revealed at the end of the series, so he cannot disclose any further details on the issue before that point. He also stated that the explanation will be magical in nature and will not involve any sci-fi elements.

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    Bare in mind too, Westeros appears to be the only 'country' in the SOIAF world that suffers the erratic seasons. I assume that seasons are felt normally elsewhere.
    – johnc
    Commented Aug 1, 2011 at 21:56
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    Hmm, I don't recall much references to seasons at all outside westeros... If other areas would have similar seasons to us, I would think that would've been pointed out. Commented Apr 21, 2013 at 8:56
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    Wouldn't 365 days be an arbitrary number to the Westerosi? It's only significance to us is that it's the period of our winter-summer cycle. (Although I guess it could be that long seasons weren't always the case, and the invention of the calendar predates it.)
    – Superbest
    Commented Apr 20, 2014 at 1:34
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    @Superbest 365 days have nothing to do with season. Matter of fact, the whole "4 seasons" thing applies only to specific regions of the Earth. Anyway, 365 days are based on astronomical observations and suns position.
    – Davor
    Commented May 2, 2015 at 13:11
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    The degree to which I trust GRRM to satisfactorially reveal this before his untimely passing is approximately the same degree to which winter is actually bloody coming. Commented May 30, 2015 at 4:19

Martin has stated that they measure years according to the solar cycle:

[What is the cycle of a year? Why do they count years when seasons are strange?]

Twelve moon tuns to a year, as on earth. Even on our earth, years have nothing to do with the seasons, or with the cycles of the moon. A year is a measure of a solar cycle, of how long it takes the earth to make one complete revolution around the sun. The same is true for the world of Westeros. Seasons do not come into it.

The Citadel: What is the cycle of a year? Why do they count years when seasons are strange?

To our mostly temperate climate perspective tracking seasons seems like the only significant reason to have a year, but even tropical cultures (such as the Maya) had devised solar calendars. The long term cycle of the stars seems to make a convenient unit of time.

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    +1 for an actual answer with a source. This should not be buried halfway down the page.
    – DCShannon
    Commented Jan 18, 2016 at 23:52

So far it has not been explained in the books. I have not seen any evidence that the characters know anything about the rotation of their planet around its axis or around the sun. The do have "name days", though, which means they do have a notion of a year. There is also a moon, and a notion of a month, which means that the moon has phases. A reasonable explanation would be that a year is defined in terms of the months, but I saw nothing in the books that directly supports that.


Could be their planet is tilted somewhat like ours, so the days get shorter in what we call "winter". But their planet may be a bit closer to their star, so the effect doesn't come with the ice and snow that comes with low temperatures.

A year seems to be about the same length as our year. "Flowering" happens at about twelve, a six-year-old baby is weird, and 102-year-old Maester Aemon is described as the oldest man in Westeros (as far as that guy knows, anyway).

The years are at regular intervals, too. Cat notes her three-year-old is half as old as her weird six-year-old nephew (and five times as fierce).

Also keep in mind that astronomy doesn't seem to be the mystery here it seems to have been in Europe circa 1000. At least not among the literate. The maesters in this world have many links in their chains, for many fields, including a bronze for astronomy (according, uncited, to Wiki of Ice and Fire). They likely realize they're orbiting a star, and can watch the others move. Even if the days don't get shorter due to wobble, they can probably measure a rotation by telescope and chart.

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    Actually, our axial tilt is entirely the cause of seasons. On a world where their axis is not tilted at all compared to the planet's revolution around the sun, they would see seasons that are years long, and probably a result of changes in solar activity. Our own sun actually has an 11 year cycle in which its sunspot activity regularly changes like clockwork. On a planet that GoT exists on, you'd tell years by which constellations rise and set, but it's unclear about why it would matter here.
    – Ernie
    Commented May 1, 2015 at 23:25

As some people have stated they could be using a lunar calendar, but there's also the possibility of a celestial calender.

Saying a year as one trip around the sun may be a new-ish concept due to a lack of a solar system model with the sun at the center is semi misleading because one can still visibly chart that progress WITHOUT seasons by looking at the night sky.

Most constellations/asterisms are only visible for a portion of the year (the exceptions circum-polar stars). Early civilizations were aware of this hence the western zodiac. The zodiac functions with a sign being determined what constellation would appear to be a part of if we could see the stars by daylight. That constellation is then visible at night at its peak half a year after the sun was part of the constellation. The zodiac along with all other constellations become visible in nice regular intervals with lengths varying in how North/South a constellation is.

If Westeros uses a celestial calendar, which given the Maester's chain has a Bronze link for Astronomy (meaning astronomy is likely more than an idle hobby) then the year could easily be determined by the appearance of a given constellation or star as marking the start of a year or month ect. The constellation or star would remain visible for some time before vanishing and eventually it would re-appear marking a return of that date.

  • The question is looking for something from the books. Is there any mention of a celestial calendar in the books?
    – Null
    Commented Nov 16, 2014 at 22:08
  • My first point was a logical assessment that one could determine the length of a year accurately without seasons or knowledge that the earth orbits the sun. Within that Maesters have a bronze chain for astronomy. That indicates that clearly astronomy is a highly important skill for running the realm and not just a hobby. Commented Nov 17, 2014 at 0:13
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    "astronomy is a highly important skill for running the realm" Indeed, as it has been for every single civilization that has ever graced the earth. :) Funny though that GRRM didn't refer to it as astrology, since before the modern age, they were basically the same. "Astrology" is Greek for "study of the stars", and would be its name today if only for the soothsayers that used it to fortell the future, and the science's need to differentiate itself from that. (it's about the only -ology that has made this change, as far as I know)
    – Ernie
    Commented May 1, 2015 at 23:39
  • This is a good point. If you only ever saw the night sky, even if the planet wasn't tilted, you could still measure a year. The constellation directly overhead at midnight will slowly change over the course of a year, and be back to the same one after exactly a year. Commented May 31, 2019 at 18:32

I got the solid impression that each year has 4 seasons as normal....but there are sort of iceages caused by magic that make "summer" and "winter" years. There were regular years and seasons in the real Ice Age. I think winter works like that and that's roughly what I'd imagine conditions in winter are like, drop Ice Age onto a medieval European society that's been partially modified as far as it could be to deal with it.

Ex: Planting cycles are mentioned, with Maesters taking temperature readings to tell when to plant which would be unnecessary if summer literally was summer with no seasons. I read summer as basically the natural temperate climate without magical interference, think America's Midwest region for much of the South and Canada for the North (like Canada, while colder the north isn't always covered in snow they still manage to support population have farms etc, it was just "summer snow" when we saw Winterfell with the dead direwolf)

Winter is an Ice Age of comparatively short duration and purely magical causes afflicting random seeming spans of years and sometimes decades (this 9 year season was abnormally long I remember, and a "3 year winter" was mentioned I think, as was one lasting an entire generation). You'd still get seasons in winter as well, such as false springs and spirit summers.

So a year has 4 "pseudo seasons (our fall winter spring and summer) and the word season in the book is meant like warm/cold cycles independent of years ("WINTER" and "SUMMER". with shorter transition periods of "SPRING" and "FALL")

So a year in summer goes like this
- planting cycle (spring)
- growing cycle (summer)
- harvest cycle (summer fall)
- summer snows (basically our winter, no big deal for westros)

A year in winter goes like this
- Fall...Very cold
- Winter...Very very cold
- False spring (still very cold but improvement.... We haven't seen one, but it's mentioned as something the Maesters can recognize and warn people that winter is still on regardless. so 1 it's recognizable and 2 it's good enough people could mistake it for winter ending) - Spirit summer (can we plant a little? is there thaw? do animals emerge from hibernation?)

So you can still track years, but SEASONS are also a big deal (and different than seasons). So far we've seen only SUMMER and FALL, but the book has been 3 years so we've likely seen seasons pass relatively unremarked aside from the summer snows at the start of the book and the planting times mentioned offhand in context of the war and winter approaching. it was something about burned fields and there not being another planting cycle in time to beat FALL

The Maesters can track seasons to advise on planting easily enough and collect and debate data to measure SEASONS and advise how much grain to store each year to avoid death by Ice Age

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    A lot of this reads like fan theory. Can you substantiate it with some quotes or references?
    – Valorum
    Commented Feb 11, 2014 at 19:45
  • it was explicitly stated that it was theory. the references that allegedly did back it up were already listed. summer snow is a thing that happens (and obviously you can't plant in that given its description), maesters telling people when to plant(not just"its summer plant away" but apparently tracking actual growing cycles, during winter there are stages called false spring and spirit summer that were mentioned as why it takes a white raven to state season changes. (the maesters know when its real.) thats it.
    – guest
    Commented Feb 18, 2014 at 12:41
  • (also i think there was something about not having another planting cycle before winter mentioned either when the ironborn trampled deepwood's crop, or that might have been the south possibly when jaimie saw his cousin but less certain of that)(and on 2nd thought I may have picked up spirit summer term from some forum I'd need to search the book)
    – guest
    Commented Feb 18, 2014 at 12:49
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    Again, "I think there was", "it was explicitly stated that" aren't worthwhile unless you can back them up with a quote or a reference.
    – Valorum
    Commented Feb 18, 2014 at 17:18
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    Justifying your post with an airy hand-wave and saying "I'm too busy to do a proper job" is hardly going to win applause from the gallery...
    – Valorum
    Commented Mar 10, 2014 at 0:47

I would very probably stick to the idea that the irregular seasons are a phenomena that postdate the civilization. Possibly, they had 4 seasons at the begining, and all that crazy-Westeros stuff, like white walkers, The Wall, children of the forest desapearing, started when the seasons went crazy, so they kept their old time measuring habits.


Obviously the Westerosi notion of a year is separate from the seasons, so therefore it must be very different to our pre-industrial year, the tracking of which had so much relevance for agriculture and keeping alive. Personally I think Martin failed to release what he'd done to the notion of a year by messing up the seasons until much later. There are a couple of ways to explain the Westerosi concept of a year. Firstly, there could be a rotating moon that takes a year to cycle. If the moon is important enough to create our months, it may be enough to create the Westerosi year. Or, the year could be a culturally significant time period, rather than a natural one. If I were Martin I would create a story based around a main character's name day, and say that there would be an original four hundred gods or four hundred saints used by the Andals, and the cycle of those god's names became culturally significant enough for a person's name day to mark their age.

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    Remember that menstruation in the books is called 'moonblood', so a cycle of their moon is probably the same as ours. Commented Jul 30, 2013 at 7:54

The first time I heard about the nine year summer, I thought that they had a double cycle of small normal seasons forming a year and a bigger cycle of short following warm and cold times like short period ice ages. But I found no further indication for that.

Now I think that that it's either a mistake by the author or a problem of describing Westeros in an earthborn language. We don't know which language the people in Westeros speak and how they measure their time. It is possible that the word year is only used to make the reader understand.


There is no explanation in the five books so far. As many have noted, time seems to be equivalent; moon cycles making up a calendar, and similar length of year, relative to our own standards. "Moons" are not fantasy; many early civilizations relied on a lunar calendar, and the Jewish, Moslem, and Chinese calendars - all still used - are all lunar-based. If people "seem older", remember that in a farming-and-herding level of technology - which still persists in many portions of our world - children have to start working, and start being both knowledgeable and realistic about life, much earlier than our typical extended adolescence through college. Consider that in the Old Testament a boy of 13 or girl of 12 was considered ready for adulthood and marriage, and that many cultures recognize 15 or 16 as being a "marriageable" age.


I asked myself the same question and I thought of a possibility:

A second moon is mentioned in the book, a moon that disappeared. Maybe that moon's cycle was 12 times longer than the moon that stayed. So they keep counting the days of that cycle, because its easier to measure the length of a season with that cycle. So they actually have two different months and not a month and a year.

Sorry if a had mistakes in spelling, English isn't my first language.


Both in the show and the book the characters have said a winter has last multiple years. A year is definetly the time period which a planet delays to go around its sun; i.e. when the planet comes closer, its what we know as summer, and when it goes further away its what we know for winter. To be compliant with gravity law a planet cannot get to have some years far away to its sun without having a transformation cicle making eliptical movements, unless it be turned this way artificially, i.e. by a god which may have an interest to have controlled the human population, causing death and destruction with an agent (starvation, and then a human killer monster) and then balance it again with a counter-agent (Azhor Ahai)

  • How would that kind of arrangement account for the summer snows the books mention? Commented Oct 13, 2016 at 13:20
  • There is a discussion about it here
    – EliuX
    Commented Oct 13, 2016 at 14:37
  • For being at the highest latitude of that part of that world and depending on climate conditions any precipitation can fall as snow, as you will find snow in Alaska on Summer.
    – EliuX
    Commented Sep 28, 2017 at 22:07

There are two obvious explanations.

The first is that the only seasons are the erratic long ones and there is some other astronomical cycle used to represent a year. There could be some reasonably obvious annual cycle such as movements of constellations of conjunctions of planets. We do know that the Citadel does make detailed but largely unspecified observations which allows them to predict the onset of winter some time in advance or at least declare that it is officially autumn. Also on a world where the major seasons are so erratic there is clearly a strong incentive to come up with a good calendar.

Also they very clearly have days so it may be that a Westeros year is just some arbitrary number of days. There is no sensible reason why this should correspond to an earth year but this may just be artistic license to make the text more readable, after all there is equally no sensible reason why they should be speaking English, especially considering that GRRRM's style is typically to keep the nuts and bolts details of the world familiar and apart form place names etc he doesn't do a lot of outright making up of details of language and culture for the sake of it.

The second option is that Westeros has mild seasons similar to earth (perhaps like the southern Mediterranean) which are noticeable but have little impact compared to the 'big' winters.


Based on how mature all the characters seem for their ages, I'd guess a year is significantly longer than our 365 days year - but how long is a day in Westeros? Ah, let's just say they're 24 hours.

I don't really think Mr. Martin stopped to consider the concept of time, because this should really have been addressed early in the books. Him for example telling us Dany is 14, only gives a rather vague indication.

But let's take Dany and Robb into account, Dany is said to be 14 but seems more like she's 15-16. And Robb is said to be 16, but seems more like about 18-19. This would mean that a year is indeed longer in Westeros, and I'd estimate that the year is about 400 earth-days long, which means that:

365 x age + (age x 35) / 365

would give you the characters age according to our "earth-year". Then again this is 100 % based on sourceless speculation.

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    How do they "seem" older than they are told that they are? Sansa for example is said to be of an age that would match the age when "real" girls get their first "flowering".So when George writes that somebody is 14 then that should indicate that they are in fact 14.
    – Jakob
    Commented Jul 17, 2013 at 12:54

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