Adding Time Duration to a Date

I’ve been searching a while but have been unsuccessful. Is there a way to add time to a set date? Or even a plug-in which will help achieve this?

In my instance, I am using a slider to animate through a construction sequence day by day. I’d like the “current” day to be added onto the start date of construction. In the example shown here, is there a way I can add 6720 days to January 1st 2024 to get May 26, 2042?