Is it the tv mini-series?
http://en.wikipedia.org/wiki/Lonesom...TV_miniseries)
If so, it is unlikely that Part 2 was shorter. If you have to input the time in order for your DVR to record, then you may have made a mistake in the start time (starting an hour late) or the channel may have broadcast it an hour earlier than you thought it would. I have seen tv channels do this, sometimes without any notice of the change.