From Longman Dictionary of Contemporary Englishkeep perfect/good etc timekeep perfect/good etc timeif a clock keeps good time, it always shows the correct time → time
Examples from the Corpus
keep perfect/good etc time• Nothing unusual - clocks behaving as before, keeping good time and continuing to emit their light beams.• Running in a clump through a crowded station, like the Bash Street Kids, keeping perfect time with chant and clap.• But like a single gear in a mechanical clock, timeless can not keep good time all by itself. 