Selected Answer
Hi Dutch and welcome to the Forum
In the attached sheet I have A2 in yellow, formatted as a date (US-style, like in your question). To determine the end of the month, you can use the Excel function EOMONTH (which needs a date, then a number of months negative or positive from that). Setting the latter to 0 makes the formula in B2:
=EOMONTH(A2,0)
and returns the last day in that month (e.g. July 31)..A2 can be copied down as far as needed
If A3 is set to:
=EOMONTH(A2,0)+1
it gives the first day of the month after A2 (e.g. August 01). A3 can be copied down as far as needed and B
2 copied down to match. All you need to change is A2 and all the dates will alter to suit.
To get column C to show date like January 2020 (iwhen it's really January 2021, you can use this formula in C2 (somewhat clumsy- but it's late here!):
=TEXT(DATE(YEAR(A$2)+1+ROUNDDOWN((ROW()-2)/12,0), MONTH(A2),1),"mmmm yyyy")
where the TEXT function qwraps around a DATE function which creates a data from year, month and date elements. The year portion depend on that of the $ fixed cell A2 and increments it after a year via the ROUNDDOWN to 0 decimal places. Copy that down.
Hope this helps.