I’d recommend to use hidden variables and groups instead of a repeating group.
Create a pop up that doesn’t show, add a group within it and name, say, var_start date.
When user land on the page, run Display data in var_start date = Current date and time.
Then create 12 groups on the page (something like this) that have a source = your hidden variable. All groups can be hidden or visible on the page load. You can connect hiding of these 12 groups with a variable on the page (for instance, if a user chooses 6 month length subscription you just add a conditional which groups should be visible in this case, if a user chooses 3 months - you add conditional to show first 3 etc.).
Your solution works well thanks for that. Though, The plans can go up to 72 months so it’s a hard job to create all of them and then do all the workflows. I’m looking at a solution to have this with a repeating group which I’m trying to make work