HelenOS sources

ts_sub            425 uspace/drv/time/cmos-rtc/cmos-rtc.c 		ts_sub(&rtc->boot_time, &uptime);
ts_sub            147 uspace/lib/c/include/time.h extern void ts_sub(struct timespec *, const struct timespec *);
ts_sub            147 uspace/lib/posix/include/libc/time.h extern void ts_sub(struct timespec *, const struct timespec *);