Spoilers for all seasons of Avatar: The Last Airbender

Preface:

Using the calendar in Wan Shi Tong’s library, the dates of the solstices and equinoxes, and comments from the characters about the passage of time, we can estimate a broad timeline for the events of the show. Shockingly, I have also found that the animators were surprisingly consistent with the phases of the moon, to the point that we can fill in the gaps down to more precise dates for most of the intervening events.

I’ve always had questions about the exact timeline of events in The Last Airbender. At first glance it seems like we don’t have much specificity except that Aang has to master the elements between the winter solstice and the vague “end of summer.” How much time does he really have? How long does he actually spend on each one? How long are they in the North Pole such that Katara can become a master in the space of a couple episodes?

In the world of Avatar, they don’t say the names of any months or dates, but the calendar seen in Wan Shi Tong’s library accepts dates in a format of 12 months and 31 days, so I think it’s safe to assume we can impose our Gregorian calendar on the world with fair accuracy. I am more confident of this after tracking the phases of the moon throughout the series, as I will describe below. The only certain dates are those of the solstices and of the Day of Black Sun. The rest I have calculated based on the phases of the moon and a couple of comments by characters about the passage of time.

Caveat

The major simplification that I had to make was to assume that the lunar cycle is an even 28 days instead of the more accurate 29.5. Because of this, if you try to map these onto the real moon phases for a real year, you will find that my estimates drift by about 1 week by the end of the series (off by about 1 day per month).

E.g. The span from 2010-2011 works as a good real-world example for the moon phases at the end of the series, but it’s about 1 week off for the early episodes. The moons phases and dates around the Day of Black Sun are very very similar to 2011, but the ones around the Winter Solstice in Book 1 are off by about a week compared to December 2010 in the real world.

The problem I had reconciling these estimated dates and moon phases had to do with two of our canonical dates. August 1 is a solar eclipse which means it’s a new moon. And when Aang talks to Roku on the winter solstice (December 21st), there’s a waxing crescent moon. Unfortunately, in the real world, these two moon phases are not possible between those two dates, UNLESS you use a 28 day lunar cycle instead of the more precise 29.5 days. For this reason, I assume the animators were using that exact simplification, at least in the first season.

Toward the end of the series, I sometimes stretch toward 29 day lunar cycles, depending on the other information available, like how many nights we actually see passing.

Assumptions

• The lunar cycle is about 28 days (I know it’s a little longer in real life; see above)
• Summer solstice:June 21
• Winter solstice: December 21
• Spring equinox: March 21
• Autumnal equinox: September 21

Book 1: Water

We have no real indications of how much time is passing before the sixth episode. Theoretically Aang could’ve come out of the ice in August, if you believe it took them four months to go from the South Pole, to the Southern Air Temple, to Kyoshi Island, to Omashu, and then to this Earth Kingdom village. I would think the first five episodes probably take roughly a month, since they’re not yet in a hurry, meaning Aang comes out of the iceberg in early November. That’s a pure guess though.

Chapter 6: Imprisoned

December 2

Chapter 8: The Winter Solstice: Part 2: Avatar Roku

December 21

No calculation necessary. We know it’s the winter solstice, so it’s December 21st. This is one of the only certain dates in the show, and it will be used as a landmark to estimate other dates.

Chapter 9: The Waterbending Scroll

Late December

We still see a waxing crescent moon, indicating very little time has passed since the previous episode; probably no more than a couple days.

Chapter 10: Jet

December 29-31

We see a full moon, so it’s been roughly ten days since the waxing crescent moon in the last episode. Combined with our estimated date for the last full moon, the three days seen in this episode seem to take place from December 29th to 31st.

Chapter 11: The Great Divide

January 10

We see a waning crescent moon, indicating that about ten more days have passed, putting us at January 10th.

Chapter 15: Bato of the Water Tribe

January 27

We see a full moon, so it’s been about 17 days since the Great Divide. That puts us at about January 27th.

Chapter 18: The Waterbending Master

February 5

We see a waning crescent moon when the Gaang arrives at the North Pole, putting us about 10 days after Bato, roughly February 5th. I’m also using this as the starting date for Aang and Katara’s waterbending training, since they begin almost immediately. All of these dates have a margin of error of a day or two anyway, since moon phases are not precise measurements.

Chapter 20: The Siege of the North

February 24

We know there’s a full moon during the siege, so it’s been about two and a half weeks since the Gaang’s arrival at the North Pole. Combined with our estimate for the date of the last full moon, this puts us at about February 24th.

Book 2: Earth

Chapter 1: The Avatar State

mid march

Counting backwards from Episode 3, I would estimate that the Gaang departs from the North Pole in mid-March, maybe around March 15th-20th. There’s not much to go on to narrow this estimate. This means Katara and Aaang studied with Master Pakku for no more than six weeks, maybe even five or less, if a lot of time passed before they got to the Cave of Two Lovers. They’re in a hurry to get to Omashu though, so I expect they only spent a handful of days, maybe a week, getting to Omashu, including the time spent with General Fong in this episode.

We don’t know for certain how much of what we see between the Gaang and Zuko is actually happening simultaneously, but Iroh gives a clue about how long it’s been.
Iroh says, “Who knew floating on a piece of driftwood for three weeks with no food or water could make one so tense?”
So we know we’re at least into mid-March, but probably not much further than that.

Notably, this is also the anniversary of Zuko’s banishment.

Iroh: “It’s the anniversary, isn’t it?”
Zuko: “Three years ago, today, I was banished.”

Chapter 2: The Cave of Two Lovers

March 21

We know this episode takes place immediately before the Gaang arrives in Omashu in the next episode, so this must take place in the early 20s of March. I like to think it’s March 21st, since that’s the Equinox.

Chapter 3: Return to Omashu

March 24

We see a seemingly full moon a couple nights in a row, putting us around March 24th (4 weeks since the last full moon).

Chapter 4: The Swamp

Late March

The moon still appears to be pretty much full, so the events of this episode must directly follow those of the previous episode. Notably, we saw three nights pass in the last episode, and we see two nights pass in this one (assuming the Gaang doesn’t fly out of the swamp at night after the episode ends)

Chapter 5: Avatar Day

Late March

We see the Gaang wake up somewhere other than the swamp, so at least one more day has passed. We see one more night pass during this episode, and we, again, end in the evening, so the Gaang presumably spends another night in the town.

Episode 6: The Blind Bandit

March 30

We see a waning gibbous moon in this episode. I would normally say this suggests that less than a week has passed since the full moon in Omashu, but we see at least six days pass in the intervening episodes, so we’ll call it a week. This is a very minor animation mistake (I should say it’s remarkable that the animators have been this consistent so far in the first place).

Notably, Aang sees a vision of Toph in the Swamp and then meets her all within about a week of his conversation with Bumi about finding a teacher.

Chapter 7: Zuko Alone

March 30

We still see a waning gibbous moon, which looks same as the previous episode. Since we don’t see the Gaang in this episode, we can probably assume the events of Zuko Alone and The Blind Bandit happen roughly simultaneously.

Chapter 8: The Chase

April 1

We see a partially obscured moon that still appears to be mostly full. Most likely it’s still a waning gibbous, as we’ve seen in the last few episodes. We know the Gaang is still just starting to incorporate Toph, so very little time has passed, which is consistent with the moon. Judging by the number of days that we have seen pass since the full moon, it’s probably around April 1st.

Aang also mentions that it’s now Spring, which is why Appa is shedding. This means it must be after March 21st (the Spring Equinox), which is a nice sanity check for our estimations so far. This is consistent with my best guess of roughly April 1st.

Chapter 9: Bitter Work

APril 3

We see the Gaang wake up somewhere different from where they went to sleep in the last episode so at least one day has passed. I estimate Aang begins his Earthbending training on April 3rd.

Chapter 10: The Library

April 20

We don’t get much information about the current date in this episode, but we do get some information about the date of the Day of Black Sun, from the calendar in Wan Shi Tong’s library. (Details included with Book 3: Chapter 10)

As far as the current date in this episode, Aang says, “I practice hard every day with Toph and Katara.” This implies that a fair bit of time has passed since the last episode. This is consistent with the date I estimate for the next episode. Notably, Aang has been studying waterbending for about two and a half months at this point.

Chapter 11: The Desert

April 20

We see a full moon, so it’s been about 4 weeks since Omashu, putting us at roughly April 20th.

Chapter 12: The Secret of the Fire Nation: Part 1: The Serpent’s Pass

April 26

We see something between a waning gibbous and third quarter moon. This put us at about April 26th, almost 1 week since losing Appa.

Chapter 14: The Tales of Ba Sing Se

Around May 19

In the Tale of Zuko, we see a full moon, so about a month has passed since losing Appa, putting us around May 19th.

Each of the Tales are probably happening on different days, especially the Tales of Iroh and Zuko, since Iroh is present in both Tales, but we can probably assume they’re all happening in May.

This also indicates that Iroh’s son, Lu Ten, was born in May, since we see Iroh celebrating his birthday.

Chapter 15: Appa’s Lost Days

Around APRIL 20 – May 19

The title card at the beginning of the episode confirms that Appa was taken four weeks ago. This is consistent with our assumption based on the moon.

Chapter 16: Lake Laogai

Around May 19

We see that the moon is still roughly full, so we’re still sitting right around May 19th. At the end of this episode, Aang is reunited with Appa, after four weeks apart.

Chapter 17: The Earth King

May 20

This episode picks up immediately after the previous one, and all in the span of a day or two, the Gaang splits up. Aang goes to meet the guru; Sokka goes to meet his father; Toph gets captured; Katara stays to help plan the invasion; and Azula arrives in disguise.

Chapter 18: The Guru / The Crossroads of Destiny

June 1-3

In The Guru, General How says, “In exactly two months, the Army and Navy will invade the Fire Nation on the Day of Black Sun.” Assuming the General was speaking very precisely, that puts us firmly on June 1st.

Two nights seem to pass between this meeting and the final fight in the Crossroads of Destiny.

Ba Sing Se falls, and Aang is near-fatally injured at the beginning of June.

Book 3: Fire

Note: the moon phases seem significantly less consistent in the first part of this season. I don’t know if the animators were just less diligent or if some episodes got shuffled around. In any case, it seems better toward the end of the season, so I was still able to make some reasonable calculations.

Chapter 1: The Awakening

around June 17

The first shot of the moon that we see is from Zuko’s perspective, as he’s returning to the Firenation. The way we cut between Aang waking up on the ship and Zuko on his ship seems to imply that they’re happening on the same night. This would make sense because we later see a full moon from Aang’s perspective.

Yue appears to Aang in front of a full moon. This puts us about four weeks since Lake Laogai and The Earth King, around June 17th. Katara comments that Aang was unconscious for “a few weeks,” which is a little longer than the two-ish weeks I’m estimating. I’m willing to call it close enough and say, maybe she was overestimating it by a few days.

Note: this is the first of several impossibly-spaced full moons that we see, but it’s the one I’m most inclined to believe, due to Katara’s comment about the timeline. I almost disregarded this one because of Yue’s influence, but between Katara’s comment and the other shot of the moon with Zuko, it seems like we can be fairly confident that there was a full moon around the time of Aang’s awakening. In my opinion, it seems most likely that Yue was able to manifest and create the opening in the clouds to let the moonlight reach Aang BECAUSE it was a full moon, and not the other way around, where she would’ve simply made it appear like a full moon when there wasn’t supposed to be one.

Chapter 2: The Headband

Mid-to-late june

There is not much information about the date, but it’s worth noting that Zuko hires Combustion Man in this episode, and the Gaang spends a few days in place while Aang goes to school.

Chapter 3: The Painted Lady

Mid-to-late june

This is the episode that gave me the most grief, because we see two drastically different moons.

First, we see the reflection of a crescent moon in the water. It’s hard to tell whether this is meant to be a waxing or waning crescent because we don’t really know what angle it’s being reflected from. Either way, it doesn’t make sense that we would see a crescent moon here because we know the summer solstice is coming in Chapter 6. We can be reasonably confident that the full moon was on June 16th, so there’s no way we could have a crescent moon before June 21st (the solstice), especially since we know there are two more episodes before the solstice. For this reason, I have chalked this up to an animation error and chosen to ignore it.

We then get several clear shots of a full moon at the end of the episode, which makes much more sense, implying that we’re still very close to the events of The Awakening. A waning gibbous moon or third quarter moon would be more accurate, since we have seen at least a week pass since the last full moon but I’m happy to call this close enough.

Notably, we don’t see Zuko this episode, so it’s likely that many of his events will be happening simultaneously with these, helping to condense this wonky section of the timeline a bit.

Chapter 4: Sokka’s Master

Mid-to-late june

We see another full moon, while sokka is making his space sword, at the end of his training. It’s hard to tell how long he spends training, but it seems to be at least a couple days.

Chapter 5: The Beach

Mid-to-late june

We only catch a glimpse of the top half of the moon in this episode, but it still appears to be near full. This is consistent with my guess that these events somewhat overlap with the Gaang’s adventures in the previous couple of episodes.

We also see the Gaang running from Combustion man during this episode, but we don’t see the moon during those parts.

Chapter 6: The Avatar and the Firelord

June 21

We know Aang communicates with Roku on the summer solstice, putting us firmly at June 21st.

We also see Zuko with a still-full moon, which would not make sense for the solstice, so we can assume that his side of the story is not happening simultaneously with Aang’s, though it obviously makes sense why they would be shown together for the audience. It’s most likely that Zuko’s scenes are happening a couple weeks later, coinciding with the next full moon in The Puppetmaster, because we already saw that Zuko was on a ship in The Awakening during the last full moon. There’s also a small possibility that Zuko learned about his great-grandfathers almost immediately after returning to the Fire Nation, while the moon still looked mostly full.

We could also just say that these eternally-full moons are animation errors.

Chapter 8: The Puppetmaster

July 17

Finally, we get confirmation of a moon that is actually, canonically full, putting us at about July 17th. This is consistent with both the solstice and our known date for the Day of Black Sun.

Chapter 9: Nightmares and Daydreams

July 28

The Gaang says the invasion is in four days, so we can easily count backwards to July 28th.

Chapter 10: The Day of Black Sun

August 1

This is arguably the clearest date we have for any episode, because we saw it explicitly written out in Wan Shi Tong’s library. The inner circle of the calendar counts 12 months and the next circle counts 31 days. In this frame, we can clearly see that the Day of Black Sun is on the first (一) day of the eighth (八) month. This post goes into more detail about how the calendar is laid out.

Since solar eclipses happen during a new moon phase, by definition, we can cross check this against our last estimated full moon date, which was roughly two weeks ago, in mid July. This is all consistent, so we can have a little more confidence in our work so far!

Chapter 11: The Western Air Temple

August 1-2

We only see one night pass during this episode, which is the night where Zuko accidentally burns Toph’s feet. This is seemingly the night between August 1st and 2nd. The kids all escape the Fire Nation on Appa after the invasion, and arrive at the Air Temple the same day, August 1st. Then Zuko shows up almost immediately, while they’re still checking the place out. This is a jam-packed day.

Chapter 12: The Firebending Masters

August 3-5

We know this is early August, when Aang begins his firebending training. The only explicit indication of the date is from the Sun Warriors’ solar calendar, but I couldn’t figure out how to read it, assuming the animators tried to make it “accurate.”

Judging by the dates of the surrounding events, we’re squeezing this adventure into a tight timeline. Zuko probably tries to start training Aang the very next day after he’s accepted into the group, which would be August 3rd. We see one night pass before they go to the Sun Warriors’ ruins, and then another night passes while they’re stuck in the goo. This means they meet the dragons on the morning of August 5th.

Chapter 13: The Boiling Rock

August 6-10

We see a basically full moon over the Western Air Temple, at the end of this episode, which is consistent with the canonically confirmed full moon in the next episode. We’re probably at about August 10th when we see this moon. Azula has a quick turnaround time to recuperate from her loss at the prison and bring the war ships to the Air Temple at the start of the next episode. This also means Sokka and Katara only reunited with their dad for about one night before getting separated again.

We see about four days pass in this episode, so it takes place roughly from August 6th to 10th.

Chapter 14: The Southern Raiders

August 12-16

We get another canonically full moon on the third night of this episode, putting us at about August 15th, two weeks since the eclipse which was definitionally a new moon . This is consistent with our known date for the Day of Black Sun and the number of nights that we’ve seen pass, and I think it’s safe to say we are well and truly past all of the lunar wonkiness in the beginning of the season.

It’s not clear exactly how much time passes after Zuko and Katara raid the ship before they find and confront Yon Rha, but we can assume this episode extends at least another day past the 15th.

Chapter 15: The Ember Island Players

Mid-August (or september 12)

We see a still-mostly-full moon, suggesting that very little time has passed since the last episode, so we’re still in mid August.

Technically this could be about four weeks later, putting us just a week before the arrival of Sozin’s Comet; however, comments made by the characters lead me to believe they’ve arrived on Ember Island fairly recently. If this is the case, however, then it’s roughly September 12th already.

Chapter 16: Sozin’s Comet

September 20

We see a clear third quarter moon above Ba Sing Se, during Part 2, putting us around September 19th. Theoretically this third quarter moon could mean it’s been either one week or five weeks since The Southern Raiders, but there’s significantly more evidence for the latter. We know the Gaang has been living on Ember Island for a while, based on several comments made throughout the first part of the finale. The White Lotus members also confirm that Iroh put out the call that they were needed, “about a month ago.” We know he escaped on the Day of Black Sun, August 1st, so we must at least be in September. Finally, September 19th, is more consistent with the “End of Summer” description we’ve heard throughout the series, since the Autumnal Equinox, marking the beginning of Autumn, is September 21st.

On (about) September 19th, Zuko is reunited with Iroh.

The following day, about September 20th, Avatar Aang defeats Firelord Ozai during the passing of Sozin’s comet, ending the Hundred Year War, after seven months of waterbending training, five months of earthbending training, and just six weeks of firebending training. This means that Aang accomplished his goal of defeating the Firelord exactly one day before the official end of summer (i.e. the day before the equinox).

• February 21, 2022