2000 – Donald is born

Donald states he was a kid when there were 6 billion people on earth. The last year this was possible was 2011. Being a "kid" to an older man normally means somewhere in the age of 5-18. So theoretically Donald could have been born anywhere from 1993-2006. This also matches up with his statement about "new gadgets coming out all the time."

The Yankees (who are featured in the film) won the World Series in 2000 and it sounds like a great round number to start from.

Note that this date is not critical to figuring out the timeline, its just a fun throw in.

2017 – Gravitational anomalies are detected

In the conference room in 2067 it is stated that NASA detected these anomalies almost 50 years ago.

Kip Thorne also says in his book that Professor Brand went back through the data two years before the wormhole discovery and found other gravitational anomalies.

2019 – The wormhole appears

In Kip Thorne's book The Science of Interstellar he imagines that Professor Brand and LIGO discover the wormhole in 2019. While not an "official" source, Kip did write the initial treatment of the script and this is the only specific date I've found in any related source. So this year is the best we have to go with and will be the year on which all other data is based.

In the conference room in 2067 it is stated that NASA saw the wormhole 48 years ago.

2025 – Erin is born

According to Google, the average age for someone to have their first child in the US is 25. So we'll say that Donald had his daughter in the year 2025. The novelization says her name is Erin. It also tells us that she was an only child.

2031 – Coop is born

The novel and the film seem to indicate that Coop is in his 40's when he leaves earth like when Donald tells him he was born 40 yrs too early or 40 yrs too late, or when the novel suggests that at the age of 124, 80 odd years had passed since Coop left earth.

This age range also matches up with an article where Christopher Nolan and Matthew McConaughey "talked about who we are as 43-year-old men, talked about who we are as [fathers], talked about our kids." Their protagonist would seem to be in the age range of 40-45.

But it just isn't mathematically possible given the facts we know about Murph's age at the beginning, Murph and Cooper's age being the same in the middle and Cooper's age at the end. Coop has to be at most 36 years old when Endurance launches.

So for now, I'm ignoring the indications and going with the "facts."

2052 – Tom is born

If we keep to about the same average of the first child being born, and assume Tom was their first child, while also factoring in Kip Thorne's date about the wormhole discovery, Donald's daughter Erin, had Tom in the year 2052.

2057 – Murph is born and the Lazarus missions launch

We know Tom is five years older than Murph so If we calculate that Tom was born in 2052 Murph will be born in 2057.

The Lazarus missions were sent out 10 years before Coop and endurance leave earth, according to Dr. Brand's explanation.

Its also fitting that the year the missions launch to save earth, the earth's eventual savior is born.

2067, April 18th – The Endurance leaves Earth

We know Tom was 15 when Cooper left earth so we just add 15 years to Tom's birth. We can also calculate this date by adding 48 years to the date of the wormhole discovery.

And if you want to get really specific...in the film an older man from the future documentary states that the huge dust storm at the baseball game happened on April 15. Coop and Murph find NASA the next night on April 16 and then spend the night there into the 17th. Coop and Donald talk that evening on the porch and then the next morning Coop leaves.

The novelization says this differently and has it occurring on May 14th. Apparently it wasn't "clear as a bell..."

2069 – Endurance reaches Saturn/Wormhole in February

8 months to Mars, 14 months to Saturn

2069 – Endurance reaches Miller's planet

After being on Miller's planet Brand says she hasn't seen Edmunds in a decade. Assuming she isn't counting the two years she spent in cryo-sleep we can infer that it took less than a year to get to Miller's planet. Additionally, after they come out of the wormhole the crew remarks that they are coming up on Miller's planet fast. So I'm guessing maybe it took them only several months (if that) to get there.

Kip Thorne also confirms this by telling us that the crew entered into the galaxy very near to Gargantua.

2092 – Coop and Brand come back from Miller's planet.

They spent a total of 3 hours and 20 minutes on Miller's planet while 23 years 4 months pass on earth.

The movie doesn't seem to indicate this as Case says it will take 45 to an hour to drain the engines. The pacing of the film also suggests they don't spend that much time down there (and I know, that's kinda the point), but in order to have 23 years 4 months pass on earth (using the ratio of 1 hour on Miller's planet equaling 7 years on earth) they have to have spent 3.3 hours on Miller's planet. Maybe they bounced around on the wave longer, or after the engines were sparked they had to come down again. The novelization seems to confirm that they did ride the wave for awhile.

Murph is now 35/36 years old. She was 10 when Coop left. Two years to Saturn, maybe several months to Miller's planet and 23 years 4 months later.

In her birthday message she says she is the same age now as when her father left. According to my timeline that would put Coop's birthday in 2031.

Again the film and novel suggest both are in their 40's (the novel specifically says when Coop is 124 that 80 odd years have passed since he left earth) but unless there's something I'm missing, this isn't possible given the facts surrounding Murph's age.

The film is also very careful to specifically state that Murph was upset because they were the same age and it was her birthday. There is a lot of detail there so it makes it hard to fudge and say they were in their 40's.

2093 – Endurance reaches Mann's planet

There has to be at least several months travel. Right before they were coming up on Miller's planet Doyle tells the group it is months to Mann's and Edmunds is even further. The way Doyle says it indicates that its more than a few so probably 6-9 which would probably take them into another calendar year.

Kip Thorne also confirms this.

2093-2100 – Endurance leaves Mann's planet

This is where things get tricky. We are told at the end of the film and novel that Coop is 124. Specifically 51 of that is spent in time slippage in Gargantua. In order for the math to work at the end with Coop being 124, and pushing 120 after the slingshot, and still being the same age as Murph when he left, we have to account for some missing time.

We're missing about 7 years. There is some outside evidence for this passage of time on earth. Tom and Lois apparently have another son in this time that appears to be 6-10 years old. The novel confirms that he is six years old though I think in the film he looks more like ten. Also Dr. Brand (Michael Caine) ages and dies.

The timeline and relative events are also pretty concrete up to this point. There really isn't any wiggle room to add in years before based on the facts we know.

We can says with a fair amount of certainty that it can't be time slippage on Mann's planet because the novel says specifically that Mann's planet is outside the time slippage zone and in the film Endurance was able to be pretty close to Miller's planet , right on the cusp of where time dilation occurs, and not be affected.

Kip Thorne estimates they were on Mann's planet only 40 days. He says this because when Cooper rescues the Endurance they are very close to Gargantua. Thorne says this possible if Mann's plant has an egg shaped orbit that brings the trajectory of the planet close to Gargantua.

So, I'm not sure what to make of this. To make the years work with what we know at the end of the film it seems that we're missing 7 or so years. Maybe they spent an extra hour on Miller's planet and didn't realize it...

Jonathan Nolan, if you ever read this please contact me and let me know :)

2151 – Endurance slingshots around Gargantua

Coop remarks "This maneuver is going to cost us 51 years." Amelia also remarks that Cooper looks pretty good for pushing 120. This matches up with the birthdate of 2031 for Cooper (give or take a few months).

2156 – Coop wakes up on Cooper Station at the age of 124

Coop is no "spring chicken" and has spent five additional earth years somewhere. Its most likely not in the Tesseract as that is in the bulk - outside of space and time. Our options appear to be:

He encountered more time slippage There is actual time in the Tesseract and that was used to transmit the morse quantum data He was in a coma after reaching Cooper Station.

I like the idea of more time slippage. Commenter Minna Aalto pointed out that there most likely would have been additional time slippage as Cooper passed the event horizon.

Murph now would be 99/100 years old. This would make sense if she and Getty get together and start a family. She tells us she has grandkids and there are some middle aged looking people in that hospital room said to be family. According to our earlier conclusions those generations would span 50-70 years. Add that to her late 30's when she solves the equation and it is plausible.

2157 – Coop reaches Brand on Edmunds planet and they live happily ever after.

Okay, I added that one in. But like most Nolan films he makes you think up your own ending.