A flick of time is actually a type of measurement.
The interval is equal to 1/705,600,000 of a second.
This may seem like an odd unit of time, but it comes from math. Basically, all the different common frequencies of waves (24, 25, 30, 48, 50, 60, 90, 100, and 120 Hz) and the 1/1000th of those intervals can be divided evenly into the number.
It is extremely small.