Possible to add 1 month to header row value when column properties are text/number?

mnydegger

I've got a project forecasting document where the total value of expected spend is summing up to a row but above that I want to be able to automatically fill in the next 24 months of dates once the starting month is inputted. Right now when using formulas like the one posted here: [how to add 6 months in a date ? — Smartsheet Community] I get the error "#INVALID DATE TYPE". Is there any way around this?

Paul Newcome

Where exactly is the starting month being input and in what format?

mnydegger

The user would be entering it in the Column Month 1 and the row Total

Paul Newcome

Am I correct in assuming these columns are text/number types as opposed to date type columns?