I have developed a database which tracks members and instruments of a music club. Now I need to build a synced base for the treasurer to use which records membership subscriptions. I have synced the list of members into the first column and their contact details in other columns. To the right, I have one column per month to record subscriptions paid. The treasurer will insert a floor or amnesty date in a column, before which subs will not be charged. In a column after the Months, I want calculate the number of months owing after the floor. Struggling to get my head round it. Any ideas? I would be grateful for suggestions.I suspect I ned a spreadsheet for this really, but would love it all to work alongside the membership database in Airtable.