There are three forms of time perception: present passage of time (interval timer), prospective timing (like a stopwatch), and retrospective timing (reconstructing past events).

“There are basically three forms of time perception that we should all be aware of. One is our perception of the passage of time in the present. How quickly or slowly things seem to be happening for us. This is kind of like an interval timer. Ticking off time. Tick tick tick tick tick tick. It's either fine slicing like that or tick tick tick. We have interval timers. I'll discuss the basis of those interval timers. We also engage in what's called prospective timing, which is like a stopwatch, measuring off things as they go forward. There's also retrospective time, which is how you measure off time in the past.”