Date Diff in excel 2010

Hello,

So I want to figure out how to write a formula for a difference in days on a "visit log". I want excel to look in multiple cells. (basically the last date entered in a row)

For example: today's date minus the last time I visited a location for inspection

I have column A as the name of the location and subsequent columns I log in every time I visit. It would make it easier for me to be able to eagle eye the locations that are due

I have 10 columns - some of which may be blank - I want Excel to know to keep looking in the cell to the left until it sees a date and subtracts the difference from today's date

Thanks in advance for any help !