Hi, Seen in srfi-19.scm:
--8<---------------cut here---------------start------------->8--- ;; -- we define it to be the same as TAI. ;; A different implementation of current-time-monotonic ;; will require rewriting all of the time-monotonic converters, ;; of course. (define (current-time-monotonic) ;; Guile monotonic and TAI times are the same. (let ((tai (current-time-tai))) (make-time time-monotonic (time-nanosecond tai) (time-second tai)))) --8<---------------cut here---------------end--------------->8--- which as far as I can see uses CLOCK_REALTIME and not CLOCK_MONOTONIC as it relies on gettimeofday(2), which has this note in its documentation: The time returned by gettimeofday() is affected by discontinuous jumps in the system time (e.g., if the system administrator manually changes the system time). If you need a monotonically increasing clock, see clock_gettime(2). -- Thanks, Maxim