$time()
$utime()

These functions return the current time in utc format. The only difference between the two is that $time() is accurate to the second, while $utime() is accurate to the microsecond. Neither function takes any arguments.

Both functions return a long unsigned integer representing the number of seconds since 18:00, 31 December 1969, which can be parsed into a human-readable format by $stime(). In addition, $utime() returns an additional integer, representing the number of microseconds past the first number that the current time is.

utc time, plus number of microseconds past utc time for $utime()

$time()      might return "850381369"
$utime()     might return "850381369 56367", which is "850381369.056367"

stime(6)