(doc-group time  «Measuring, manipulating and displaying time.») (defdoc (sleep sec)  «Halt the StreetLISP VM for the specified duration of time in seconds.b»  :doc-example  «(sleep 0.1) ; sleep for 100ms»  :doc-group time) (defdoc (nanoseconds-monotonic)  «Return the number of nanoseconds passed since the first call to this   function.    The first call will always return 0.»  :doc-example  «(nanoseconds-monotonic)   ; ↳ #u64(0)   (nanoseconds-monotonic)   ; ↳ #u64(47840)»  :doc-group time  :doc-see time-now) (defdoc (time-now)  «Return the number of nanoseconds since Epoch (1970-01-01 00:00:00).    This measures the system-wide real (wall-clock) time.»  :doc-example  «(time-now)   ; ↳ 1746494461277334928»  :doc-group time  :doc-see nanoseconds-monotonic) (defdoc (time->str sec)  «Return the number of nanoseconds since Epoch formatted as time and date.    This is the opposite of `str->time`.»  :doc-example  «(time->str (time-now))   ; ↳ "Tue May  6 03:21:01 CES 2025"»  :doc-group time  :doc-see str->time  :doc-see time-now) (defdoc (str->time str)  «Return the number of nanoseconds since Epoch from a time and date   formatted as a string.    Because the supported format is limited, the returned value will have   precision in seconds at most.»  :doc-example  «(str->time "Tue May  6 03:21:01 CES 2025")   ; ↳ 1746494461»  :doc-group time  :doc-see time->str  :doc-see time-now)