`get_dst_transitions` probed the offset once every 24 hours from the start time and reported a change at the first probe after it, up to a day late, so events, review items and recordings near a transition were grouped into days with the old offset. A transition after the last daily probe wasn't found at all. The end of the range is probed too now, and a probe that sees the offset change bisects the interval to the second of the transition.
Josh Hawkins
8aa0ddf740