Dates plus or minus a certain amount of days.

Good afternoon.

I know the title of my email is a bit confusing, allow me to explain

My job uses equity based billing, so to figure out certain billing dates, I need to have the next billing date minus 5 days. I have to repeat this multiple times, which is why I am looking for a formula for this.

For example, if I put in 05/10/2018, I would want the next cell to display 06/05/2018.

Is there a formula for this? I've always had bad luck with formulas for dates.

Thanks for your help.

-MP-