An electrical device for regulating photoperiod, fan, etc., a timer is a must in all cultivation operations.
Merriam-Webster Online Dictionary
timer (noun) one that as - times
a) - timepiece , especially a stopwatch for timing races
b) - timekeeper
c) a device (as a clock) that indicates by a sound the end of an interval of time or that starts or stops a device at predetermined times
Merriam-Webster Online Thesaurus
timer (noun)a device to measure time
SYNONYMS:
chronometer, clock, timekeeper, timerRELATED WORDS:
alarm clock, atomic clock, cuckoo clock, grandfather clock, time clock; clepsydra, hourglass, sandglass, sundial, water clock; chronograph, stopwatch, watchcountdown device, timekeeper, chronometer, stopwatch, time tracker