In Back to the Future II , on November 12 1955 the DeLorean with Doc in it gets struck by a bolt of lightning, sending him back to 12 AM 1 January 1885. The potential for this is alluded to previously when we see the time circuits flickering to this date. I can understand why the time circuits would default to 12 AM because in 24 hour time that's 00:00. I can also understand why it would default to 1st of January, because that's the beginning of a year. So far so good; the time circuits are defaulting to a 'base' time (i.e. the beginning). What I don't understand though is why did the year default to 1885 ? Surely it would make more sense for the year value to default to the year '0000', or '1900' or some other such date which marks the beginning of a century or millennium. Answer Digital time is stored as an offset from some date and time in the past, known as an epoch. For example, on MS Windows computers, the current time is measured as the nu...