PS/BS
when the proctor says "you may begin" ....
write down the time he said it at the beginning of your booklet
write down the time after the first three 32 minute intervals, corresponding to the end of the first and second set of discretes (1/3, 2/3 through test), and the five-minute warning (when you should be wrapping up.)
e.g.
9:04 (begin)
9:36 (should be near 1st set of discretes)
10:08 (should be near 2nd set of discretes)
10:40 (approx. "5 minute warning" from proctor)
this is much quicker than having to "guesstimate" with one's watch, and eliminates any anxiety over time, since one can always flip to the benchmarks to gauge oneself.
for verbal, there are no "benchmarks" (i.e. discrete sections), so i write down 60 minutes after the start-time to give me an advanced warning if i'm behind, so that I can start skimming the last few passages.
e.g.
12:01 (begin)
1:01 (25 minutes remaining, should have 2 or 3 passages left)
It seems complicated, but it takes only seconds to write the times in one's booklet, and can then be referenced easily and quickly!