Whenever you travel through time the DeLorean updates the time circuits to reflect the current date and time. How does it know the current date and time of its arrived destination?

I guess what I am asking is, when the lighting stuck the delorean and jumped it back to 1885. Did the time circuits know it was 1885, or did it not know, because it wasn't entered.

enter image description here

  • I don't understand the question. You program in the time for the destination. Jun 28, 2012 at 18:26
  • 1
    That is a really interesting question. Jun 28, 2012 at 18:45
  • 1
    I'd guess it's like a odometer; it knows how far it went through time. Jun 28, 2012 at 18:50
  • 1
    @JackBNimble The flux capacitor obviously. Just kidding. Jun 28, 2012 at 19:38
  • 1
    When you think about it, there is no such thing as the present time. By the fact that in the BTTF universe time travel is possible, it means that it is always the present - what I mean by that is that all time (1885, 1955, 1985, 2015) are all simultaneously occurring - on what basis would you say that 1985 was the present time when you were in 1955? Apr 3, 2014 at 6:14

2 Answers 2


Before the lightning hits, you can see the time circuit experiencing bugs and the destination date continually changing between 1955 and 1885 (as you can see in this video). Obviously, we can assume it settled on 1885 since this is when it sent the DeLorean. The date was thus "entered", even if it wasn't intentionally. As to your question, I believe the time circuit, once the time travel has been completed, sets the current time as being the same as the destination time used in the voyage.

A clock doesn't "know" what time it is. It simply calculates how much time has passed since a certain reference point. If you give it a new reference point, such as by changing the current time it displays, it will simply update from that point on. How it calculates time varies greatly depending on the type of clock, but, in 1985, the year the movie was made and originally set, computers and electronical items were already able to keep track of the passage of time through internal clocks.

The DeLorean can safely be assumed to possess one such internal clock and, therefore, keep track of time. When the DeLorean was struck by lightening, the time circuit's clock most likely adjusted it's current time to JAN 01, 1885, 12:00AM after completing the voyage. From then on, it kept updating the current time just like any other clock.


It knows what time it is because when you travel through time, you input where your going and then it goes there. That's how it knows. If your asking how it knew the first time around, then I'm sure that Doc just put in what the original present time was.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.