When setting the time with a timeline view today you are not always able to set an accurate time (depending of resolution on screen). It is very hard to set it to 15:00 or other specific times. It should snap to e.g. 5 minutes intervals. If user needs to publish at 14:47 he should rather specify that manually as it is more common to lock at a round time like 14:40, 14:55 or 15:00.

See attached movie, not able to select 15:00 in this resolution.