Im trying to sum a column based on other columns containing certain criteria.
For instance the example below im after the sum of idle delays on the 1st.
But it gets more complex when i want the sum of any delay containing "idle",
in the week 1-7/1/09

Eg.

Date Delay Time(h)
1/1/09 Idle time 0.3
1/1/09 Idle / external 0.4
1/1/09 Breakdown 1
2/1/09 Breakdown 2
2/1/09 Idle / mech 3
2/1/09 Idle / external 4