I never need to insert timestamps with a granularity of smaller than 5
minutes, and hardly ever smaller than 15 minutes. So it would be
really nice if when over the minute portion of a timestamp,
org-shiftup/down increased/decreased the minute value in multiples of
5, 15, or whatever other value the user wants to configure. So for
example, that way I could postpone the start/end of an appointment by
15 minutes with a single key chord.
For backwards compatability, the granularity could still default to 1
if that's the behaviour the majority of people prefer.