Abstract: A time interval counter permits the time interval between a first signal and one of a series of timing signals to be measured to less than .+-.2 nanoseconds without using microwaves and high power-consuming devices. The time interval counter uses a first passive delay time operated from the first signal, which occurs at an unknown interval from the timing signals, to produce a plurality of binary outputs spaced from each other by known equal time intervals that are substantially less than the interval between the timing signals, and a second passive delay line operated by the timing signal, which occurs after the first signal, to produce a plurality of sequential outputs spaced from each other by a plurality of known sub-time intervals that are substantially less than the time interval between the plurality of binary outputs of the first delay line.