|Make believe that you are one of us sitting out here on the interweb, where we can't see your spreadsheet. Now go back and read what you've posted.|
Do you think that you have supplied enough information for us to help you?
We have no idea what =+Summary!C1 returns or why you want to replace a formula with a date.
The one thing we can tell you is that the plus sign in your formula serves no purpose.
Click Here Before Posting Data or VBA Code ---> How To Post Data or Code.