With C-c C-x C-i and C-c C-x C-o we can get measurements on how much time we spend on tasks:

:LOGBOOK: CLOCK: [2016-11-21 Mon 22:50]--[2016-11-21 Mon 22:57] => 0:07 CLOCK: [2016-11-21 Mon 22:30]--[2016-11-21 Mon 22:30] => 0:00 :END:

But the smallest unit is a minute. How can we get measurements in seconds?