So, when exactly is "OTH"?

[Doug Drown]

Whenever the power goes out, I customarily reset my VCR clock (yeah, I still have one of those) to :00 on a network or cable station.  I've discovered, however, that "on the hour" on one channel may not be "on the hour" on another.  For example, we get both WCSH in Portland and WLBZ in Bangor, Gannett's co-owned NBC affiliates in Maine.  WCSH's :00 is a second ahead of WLBZ's.  All the network programming is a second or two off, as well.  Same with the ABC affiliates here.  What gives --- and how can I find a reliable way to set my clock?  (I know, I know, go get an atomic clock . . . )     -Doug