Recovery time by firstbeat is just useless nonsense

Yesterday I did a relaxed 10k at 5:10 per k. Nothing special. Recoverytime: 44 hours. (Looks like a bit on the highsite)

20 hours later I did a slow long run of 34k at 5:40 per k. Total recoverytime after this run 22 hours. (Did it forget the remaining 24 hours?) 

It looks like it resets recoverytime after each run, or does some really stupid calculations.

One way or the other, it just on of these not really working features on my forerunner 935.