Marking a column based on date in another column

I have a worksheet that keeps track of members for an organization. One column, let's call it B, notes the month when the members are due to renew their membership. Our organization requires that members be notified of pending renewals one month before, the month of, and one month after they're due to expire. Rather than having to re-sort the database every time I want to pull up this information, I'd like to create a second column, column C, that puts a character next to the names of members who are about to come do. Ideally this character would change depending on what stage they are in the renewal process (a month before, month of, month after). Super ideally, if this is even possible in Excel, members who haven't renewed by the last month will automatically be moved to worksheet two, which contains recently lapsed members.

What sort of code would I need to do this? I've tried googling for it, but I can't find quite what I'm looking for, and I have no script savvy whatsoever. Thanks in advance!

Can you post a sample workbook that has dummy data but is organized exactly as your current workbook is?

See attached for both problems.

Formula in I3 of the current sheet tells you if the date is in the previous month, this month or next month...

Formula in A3 of lapsed sheet, extracts only the names that have a "Month After" renewal date.

The formula assumes a database of only 100 rows, you can change the ranges in the formula, then you must confirm the formula with CTRL+SHIFT+ENTER keys to get the { } brackets to appear, then copy it down as far as you want and across as many columns as necessary.

Note: There is a formula in I1 of the lapsed sheet that counts how many "Month Before" there are. If you change that title, then you must change that title in that cell formula too and in the formula in A3, copied down and across.