How to fill field in parent issue with values of children (timespent)

[Fabian van den Barselaar]

I have the following situation :

1 Epic with 2 children : issue 1 & issue 2

Epic contains 2 fields :

"Original estimate" - 200h

"Credits used" - 0h

Now I want 1 of the following solutions:

1. When time is logged on issue 1 or 2, it should update the Credits used field of the Epic. When work log is removed it should also adjust the credit used.

2. Each day 17.00 hours the field Credit used should be updated with the values Time spent of issue 1 & 2. 

Anyone a nice solution?