Bug: Month delays calculation out by a month

[ipokkel]

Setting the months for a delay is calculated one month short, e.g. setting a 3-month delay with YY-M3-DD creates a delay for the checkout on 03 June 2021 at the end of the month two months after the day of checkout, 31 July 2021.

[andrewlimaza]

It's correct functionality that it's out by 1, for example:

Y1-M2-01 is the following month, whereas M1 is set to the current month.

If you need 3 'whole' months, you would set the subscription delay to Y1-M4-01 for example.