Updated: 2022/Sep/29

Please read Privacy Policy. It's for your privacy.

TIME_SECOND(9)             Kernel Developer's Manual            TIME_SECOND(9)

     time_second, time_uptime - system time variables

     #include <sys/time.h>

     extern time_t time_second;
     extern time_t time_uptime;

     The time_second variable is the system's "wall time" clock.  It is set at
     boot by inittodr(9), and is updated periodically via timecounter(9)
     framework, and also updated by the settimeofday(2) system call.

     The time_uptime variable is a monotonically increasing system clock.  It
     is set at boot, and is updated periodically.  (It is not updated by

     All of these variables contain times expressed in seconds since midnight
     (0 hour), January 1, 1970, UTC.

     The bintime(9), getbintime(9), microtime(9), getmicrotime(9),
     nanotime(9), and getnanotime(9) functions can be used to get the current
     time more accurately and in an atomic manner.

     Similarly, the binuptime(9), getbinuptime(9), microuptime(9),
     getmicrouptime(9), nanouptime(9), and getnanouptime(9) functions can be
     used to get the time elapsed since boot more accurately and in an atomic

     clock_settime(2), ntp_adjtime(2), timespec(3), hardclock(9), hz(9)

NetBSD 9.99                     April 17, 2020                     NetBSD 9.99