My brain tells time automatically.
On weekdays, I hit the snooze alarm twice before arising. I find I often turn over to check the time 10-20 seconds before the alarm goes off again.
I do not reset my alarm on the weekends, even though I sleep in an hour later. I like the flexibility of perhaps getting up and doing a little something, such as putting in a load of laundry, and then going back to bed.
This morning, I hit the "off" not the "snooze," and rolled over. But I slept the exact number of snooze alarm minutes and got up, noting the time. This happens often, and is mildly curious but hardly a big deal. My brain must be reacting in some pavlovian fashion to repitition...So?
I made my coffee and stood out on the porch. I heard two beeps, softly but distinctly. Had I hit snooze by mistake? No, it stopped immediately. Did one of the neighbors have a similar alarm, and the beeps had carried across the 50-100 feet by some trick of wind or window? Extremely improbably.
I looked inside -- it was the exact time of the second snooze going off. My brain had supplied the signals to my hearing centers, even in the absence of actual sound. The brain tells time with fair accuracy.