Date calculation

Hello,

I've created a spreadsheet (excel 2003) for the purpose of tracking work order activity. It would be great if I only needed to update one cell and have 2 other cells populated with the correct date information.

Attempted to right an IF statement for the work order with a status of "Pending" to automatically flag with current date (=IF(cell="Pending",cell=TODAY(), G7="Closed") INVALID result

I would like to be able to determine the following with the focus on "Status":

- If status = "Pending"; leave "Resolved Date" blank; AND calculate the number of days pending
- if status = "Closed"; update "Resolved Date" with today's date AND calculate the number of completion days

- how did it take to complete the work order (= DAYS360(cell, cell)
- how many days are still pending (=cell-cell)

I really hope there is a way to do calculations with dates.