Fix behavior of org-timestamp-change for explicit number of day changes
* lisp/org.el (org-timestamp-change): New optional argument UPDOWN.
Use this to identify calls from org-timestamp-up/down, so that we can
skip by rounding minutes in this case.
(org-timestamp-up):
(org-timestamp-down):
(org-timestamp-up-day):
(org-timestamp-down-day): Call org-timestamp-change with the
updown argument.
This function used to look only if there was a prefix argument in the
current interactive call. Now we have an explicit marker indicating
that the function is called from the updown commands.