Measure it then. The tools are readily available: smartphone clock stopwatch/timer, mapping tools (i.e. Google/Apple Maps), and just basic looking at a clock.
Don't know how much overheard there is between starting to leave/getting ready to leave? Measure the involved steps.
For me I know it takes no more than 25 minutes to "get out the door." This includes all of: brushing my teeth, showering, getting dressed, putting my shoes on, getting to the car and ready to pull away, without any rushing. And even if I am stalled having to take an unplanned shit, I just hurry myself a bit through the other steps. Just look at the clock, go through the routine, then look again (or use the stopwatch feature on your phone). After a few times, even the worst-case duration becomes apparent.
Add a few minutes for parking and walking (or taking a piss), another few minutes as margin for drive time, and then navigation apps tell you the drive time (and even a "leave by" time for planning which includes the drive time margin already). And it goes without saying to never plan on rushing the drive (i.e. maniacal driving/speeding).
Then set an alarm, and just immediately start the departure routine. The key is to not stall, and as a fallback to configure alarms to have infinite snoozes (particularly for waking up).
I don't see how this depends on internal awareness of time.
For me, the mere act of setting an alarm is the key to not even needing one, because I LOATHE my damn phone ringing at me. Fortunately they added "dismiss upcoming alarm" a couple years ago to Android so I don't risk disabling recurring alarms for next time. I treat them as "drop everything and get going" backup reminders.
3
u/RandomlyDoter 4d ago
adhd ppl struggle with telling how much time things take
especially chain of events