Excel 2007 : Format entire columns based on date at head of column

Hi, I hope someone can help!
I have a spreadsheet of orders arranged in columns (works better for me than in rows), where the head of each column give the date that the order is required by. I want to conditionally format the sheet so that when a particular order date has past, the entire column for that order becomes greyed out.

I've had a go myself, using the formula B1<TODAY() with strange results! The row with dates in has formatted correctly, but the rest of the sheet has formatted regardless of the date, and only formatted empty cell or ones with numbers in, not text ones. Please help! Please see attached file.cake orders test sheet.xlsx

Change the conditional formatting formula to

=B$1<TODAY()

The $ sign means that the formula will always refer to row 1, even if the cell with the conditional format is in a different row.

Without the $ sign, the comparison will be with each individual row.

Perfect Mate, works great now! Thank you