Today function causing Modified (date) to update every day

Hi Darrel, 

There is currently no timestamp function in Smartsheets. Use of Today() will always update to the current day that the sheet is accessed. Today() works great when you are calculating days since, or days until based on the current date that the sheet is accessed. 

There are third party solutions for time-stamping like www.zapier.com. 

J. Craig Williams's response to this community article highlights how he did it. https://community.smartsheet.com/discussion/insert-time-stamp

I recommend submitting a product enhancement request.