For me I just insert something like a horizontal line as a sort of "Break in the timeline" and make a brief mention of the amount of time that passed.
Example:
Why do I need to focus on this for three. entire. hours...
I write stuff in a google document and then copy paste it into scribble hub. The problem is that the horizontal lines I insert to signify a time skip don't seem to be showing up when I do so and I have to manually re-insert them.