excel - calculate date based on number of hours / planner

I'm trying to figure out how to auto generate/populate a column in excel based on the number of hours filled in another column:

Start date: 04-08-2011
Hours in one day: 8

Issues   Hours    Date
part 1 | 2      | 04-08-2011
part 2 | 6      | 04-08-2011
part 3 | 2      | 05-08-2011
part 4 | 2      | 05-08-2011
part 5 | 8      | 06-08-2011
part 6 | 2      | 06-08-2011

So when i add issue 'part 1' the date starts @ the start date, when i add hours or 'parts' it continues to use the start days until it reaches 8 hours and continues to the next day.

Also when i开发者_运维问答m adding a row between the existing rows it automatically recalculates the dates.

Anny ideas where to start? Tnx

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If I understand what you are asking correctly, and assuming start date is in Cell B1, and hours in 1 day B2

And data header in A4:C4, with data below

Then put the formula '=$B$1+INT(SUM($B$5:B5)/$B$2-0.1)' in C5 Copy C5 down and it should generate the date automatically

The '-0.1' is to account for exactly 8 hrs being allowed in 1 day