org-habit : time-dependent habit

Question

For instance, I have the following habit "sleep before 23h"

** TODO sleep before 23h                                  
   SCHEDULED: <2019-09-07 sam. 23:00 +1d>
   :PROPERTIES:
   :STYLE: habit
   :END:

And I mark it as DONE on my agenda each time I'm going to sleep. However, whether or not I've done it before 23h, org-habit considered it as done in time since it's day-based. Is there a trick to change its behaviour so that "sleeping after 23h" in this case is considered overdue?

Answer 1

For starters, my suggestion would be to use DEADLINE: rather than SCHEDULED:. See The Org Manual: Deadlines and scheduling for an explanation of the distinction. Namely:

SCHEDULED Meaning: you are planning to start working on that task on the given date.

and

DEADLINE Meaning: the task (most likely a TODO item, though not necessarily) is supposed to be finished on that date.

You may wish to set a SCHEDULED: value as well to reflect the earliest you anticipate going to bed.

Answer 2

I find this question quite interesting as trying to log my sleep schedule has been a conundrum for me as well : when you get to bed isn't the time to log it, and the day after isn't accurate, really.

Also, the real info I aim for is the amount of sleep I had and if sleeping time and wake-up time are stable or not.

Trying to implement @ebpa answer gave me

** TODO sleep before 23h
   SCHEDULED: < 22:30 +1d>
   DEADLINE: < 23:00 +1d>
:PROPERTIES:
   :STYLE: habit
   :END:

Now I'll try to get emacs/org-mode to compute sleep time ...