I had always wanted to know the exact amount of time that Marty spent during the course of his travels. Since every trip was time stamped, I was able to calculate the exact amount of time that Marty spent between his initial departure at Twin Pines Mall, Oct 26, 1985 at 1:35 AM, to his final arrival at Eastwood Ravine, Oct 27, 1985, at 11:00 AM.

I am only calculating the time that Marty spent. It is very easy to show how much time Einstein spent (1 minute); therefore, Einstein was displaced exactly one minute from his relative age. I didn't track down Biff's nor Jennifer's times, although they could have been calculated from the Delorean Time Travel Display modules. Finally, Doc had taken trips to undisclosed times and locations that cannot be calculated from the movie or accompanying authorized documentation.

My quest for this calculation came from the OUTSTANDING video, ""Back to the Future: The Enchantment Under the Sea Dance Revisited" (2005)", by MuhlFly. I wanted to see EXACTLY how much older "Old" Marty was compared to "Young" Marty. That difference is shown at the end.

Anyway, here are all the trips involving Marty and the Delorean, and the cumulative time that Marty spent during each jump:

The two Martys' age difference in 1955:

Marty arrived the second time in 1955 on November 12, EXACTLY one week, or 168 hours, zero minutes, after he arrived the first time on November 5. Therefore, to calculate his age difference between his two instances in 1955 is as follows:

1. Take the cumulative total taken at the time Marty jumped back from 1985 to 1955 the second time, which is 203 hours 02 minutes

2. Next, subtract the 1955 arrival time difference, 168 hours.

3. When Marty arrived on November 12, 1955, he was exactly 35 hours, 2 minutes older, or almost a day and a half older, than his original self the first time around.

EDIT NOTES SINCE ORIGINAL POST: First, I confirmed that the departure date/time from 1985-A was 2:42 am, which was consistent with the movie continuity. I originally had sourced an analysis that indicated the time was 2:42 pm, which was wrong. The asterisked changes are removed as the "am" designation has been confirmed correct.

Another edit note: Hot_for_Dockie mentioned that the departure time from 1955 to 1885 for Marty was on the 16th of November, not the 14th. Again, the original source was wrong. As I do not have BTTFIII handy to look at, I went by his column. It does make sense that Marty and 1955 Doc would have to spend more than 1 day to come up with the items to ensure the Delorean works. In addition, the BTTF site does confirm a November 16th departure date.

This calculation adds 48 hours to Marty's total cumulative time, and does not change the age difference of "Old" Marty and "Young" Marty in 1955.

That was very well worked out. Good job!

A very interesting read. And welcome to the board, Serious Excrement :)

Very nice (and I love the user name. :D) I never noticed the P.M. thing before -- I agree, probably a mistake.

However, I think you've got a small glitch in your math there -- Marty departs for 1885 on November 16th, not the 14th. They spend the 14th getting the DeLorean out of the mine, and Doc needs some time to build his vacuum-tube control "chip."

Fair enough. In fact, I had originally obtained the time stamp sources from awhile back from HERE, but had only corroborated the first two movies myself.

I have also just read the BTTF website, and they had a lot of information on the DeLorean chronology, but some time items were missing, which had been included in the above list.

To make it clear, then, Marty took off on the 16th, not the 14th, of November 1955, for his trip to 1885. I will adjust the calculation to make it so. Thanks!

PS: I seriously thought of "Serious Crap", but since we are "scientists", "Excrement" won out.