Compute future date

I would like to calculate a future date, for example to determine when a medication refill is due. I would enter today's date plus 28 or 30, with format to indicate "date prescribed" and "next prescription due," for example
***Solved!

You can use the shift setting of the {time} command to select a future date:

For example:

28 days from now: {time: LL; shift=+28D}
30 days from now: {time: LL; shift=+30D}