adding up hours as numbers doesnt match hours as time format

[DBenz]

Hi,



My initial column was number, so 8 2 3 0.5 0.25 etc for hours I estimate tasks of the job will last.
then having created start and end times columns, several for each task, they obviously generate hh:mm:ss type results when deducting start time from end time.
I create a new column beside the initial numbers of hours per task, and populate it manually so 8 hrs is now 08:00:00, 0.25 is 00:15:00 etc


number column added to 48.25 hrs, but this new column , using =C2+C3+C4+C5+C6+C7+C8+C9+C10+C11+C12+C13+C14


adds up to 23:45


Why ?


I then use autosum on the first 19 rows and success, include a further 6 and failure, tackle the last few rows and success, do it in three chunks 19, 6 and 14 rows and success for each, its as if autosum bottles out of more than 19 ? One would think the format was corrupt for the 6 rows, but on their own they behave.


I have totals of 20:15 07:00:00 and 21:00:00 but adding then these together using a+b+c method I get 00:15:00 so that fails.


I could post the file but cant see a way of doing so.


I simply want rows as tasks, a column for how long I estimate each task to take, then start and end time cells for the times I start and end each task, and several per task to allow for human breaks ! then a column that subtracts the starts from the ends and adds them up for a total, then beside that a column deducting that from the estimate to give a 'credit' or 'debit' figure so I can see if to panic or relax !





anyone care to create such, sounds simple.


DBenz