$err = ( $ms < 100000 ? 'wrong' : '' );
printf "Seconds since epoch (float):  %.6f\n", $sec;
# $sec is a float, print it like that...
printf "Seconds since epoch (list):   %d.%d  $err\n", $s, $ms;
printf "Seconds since epoch (float):  %.6f  $err\n", $float_t;