Conditional formatting based on value in diff sheet

Hi all,

I'm looking to have conditional formatting on Sheet3 if any of the dates in Sheet1 A1:A100 match DAY in current cell...

On sheet three I have a calendar type setup with dates for each month. On the first sheet column A is used to list days absent. What I would like is for sheet three to change the color of the cell if the date is listed on sheet one. I know this is not the best program for something like this, but hoping I, with your help, can make it work.

So for example: Sheet 3, cell B5 would change to red because listed on Sheet 1.

Sheet is attached. Thanks in advance.