date - what is a fractional second?

Question

I am trying to understand what a fractional second is. I found a fractional second,here:

double uhd::time_spec_t::get_frac_secs  (   void        )    const
     Get the fractional part of the time in seconds.

Returns:
     the fractional seconds

What exactly is a fractional second represented as a double? Can someone give me an example value and how that translates in to seconds?

Answer 1

Fractional second is the part of the time that is not an integer. So if you have a time like 12345678.9 the fractional second is 0.9