Create track log from snail trail

I have created a personal track log from my snail trail. I can see the resulting track log is divided into segments (1 segment per day). I want to be able to extract just some small portions of "log" from those daily segments. Is there any practical way to do this. Deleting almost all the red dots for a whole day is just not workable.
Also it appears that if I do edit a day's segment, that when I save this it overwrites the track for that day, so how do I create several short track logs from one day's segment?