code/controllers/subsystem/timer.dm

BUCKET_LEN	Controls how many buckets should be kept, each representing a tick. (1 minutes worth)
BUCKET_POS	Helper for getting the correct bucket for a given timer
TIMER_MAX	Gets the maximum time at which timers will be invoked from buckets, used for deferring to secondary queue
TIMER_ID_MAX	Max float with integer precision
/var/SStimer
/datum/timedevent	This is the actual timer, it contains the callback and necessary data to maintain the timer.
/proc/_addtimer	Create a new timer and insert it in the queue. You should not call this directly, and should instead use the addtimer macro, which includes source information.
/proc/deltimer	Delete a timer
/proc/timeleft	Get the remaining deciseconds on a timer

Define Details

Controls how many buckets should be kept, each representing a tick. (1 minutes worth)

Helper for getting the correct bucket for a given timer

Max float with integer precision

Gets the maximum time at which timers will be invoked from buckets, used for deferring to secondary queue