With times clearly in UTC, tv_sort incoorectly reports overlaps and errors, e.g.:
overlapping programmes on channel I34156.labs.zap2it.com:
Rachel's Favorite Food at Home at 20111030000000 +0000-|20111030003000 +0000
and Endless Feast at 20111030010000 +0000-|20111030013000 +0000
programme on channel I10035.labs.zap2it.com stops before it starts: 20111030003000 +0000, 20111030010000 +0000
Clearly from the times as shown, there is neither overlap nor start/stop discrepancy.
N.B. The UTC times reported are around where local politicians have decided to implement so-called "Daylight Savings Time" changes, but that should be irrelevant to tv_sort as the specified times are clearly in UTC, which has no such changes (N.B. "+0000").
UTC has been intentionally specified in the xmltv configuration specifically to avoud such issues, but despite tv_sort source line:
use Date::Manip; Date_Init('TZ=UTC');
tv_sort appears to be attempting to inappropriately impose time shifts.
Tested with xmltv versions 0.5.59 and 0.5.61 (no difference, which is unsurprising as filter/tv_sort is unchanged)