[O] [BUG] Scheduled items in past show time of day in agenda

[Matt Lundin]

Hi everyone,

With commit 69ec6258b65a5d317f0dcb275ec2d5a90f72f191 I find that
non-repeating timestamps with a time-of-day designation continue to
appear at a particular time in the agenda even when they are in the
past.

For instance, using emacs -Q, i find thagt the following item scheduled
for yesterday...

* A scheduled item
  SCHEDULED: <2016-11-28 Mon 17:00>

...appears in the agenda for today at 17:00...

Day-agenda (W48):
Tuesday    29 November 2016
               8:00...... ----------------
              10:00...... ----------------
              12:00...... ----------------
              13:57...... now - - - - - - - - - - - - - - - - - - - - - - - - -
              14:00...... ----------------
              16:00...... ----------------
  test:       17:00...... Sched. 2x:  A scheduled item
              18:00...... ----------------
              20:00...... ----------------

The expected behavior (i.e., no time of day designation if it is not the
scheduled day) is the following...

Day-agenda (W48):
Tuesday    29 November 2016
  test:       Sched. 2x:  A scheduled item

Thanks,
Matt