I just queued up jobs for a physics simulation that are 5 compute-centuries long:
6 jobs x 11.5 hours x 16384 nodes x 4 cores/node = 5.16 centuries.
I'm expecting the runs to be finished in about a week
If this ran on a single core and I wanted it to be finishing in about a week, I would have had to start them in the year 1495 (the most interesting wikipedia note for that year is Friar John Cor records the first known batch of Scotch whisky).