Getting the value in one column from a formula on another column in excel

Question

I have an excel table that looks like this:

Date         Original       Actual
11/10/10     15             12
12/10/10     12             10
...
24/10/10     2              1
25/10/10     -2             0

I want to know the date at which the original column becomes negative, 25/10/10 in this example.

I've managed to figure out the value using this formula: =MAX(IF(D63:D91 <0,D63:D91)) which tells me -2.

I just want it to look at the date column where the original value = -2 and tell me that date, but I can't figure out a way to do this at all!

Anyone have any ideas?