isWithinShow not correctly handling end times after midnight

[RocketMan]

isWithinShow is currently special casing a show end time of '0000' (midnight) but does not handle end times after midnight; for example, 2300-0200. Such a showtime will cause isWithinShow to indicate times are not within the show when they really are.

The correct solution is to test if the end time is less than the start time; if so, then the end date needs to be increased by 1, because it means the show ends the next day. Thus a show on 2020-01-20 from 2300-0200 will have end time 2020-01-21 0200.