Sometimes invoices or bills can be received late and so you might need to post a "catch up" release schedule.
In this instance you have 2 options. You can either:
Calculate the amount you need to "catch up" in the current month and input this and all future releases as adhoc amounts (see this article for more information); or
Select a date in a prior period to start the release from.
To explain this in more detail, lets walk through an example:
Bill for $1,200 for a subscription from January - December, received in February (after you've closed the January books)
Raise the bill in February and post as normal
Release in February should be 2 months worth equal to $2,000
In Mayday you can select to start the release in January. In the schedule you would then see:
a ($1,000) release in January
a net amount of $11,000 in February (equivalent to the $12,000 prepayment less the $1,000 release)
($1,000) release in March - December
If you have not locked your books, you could update the January journal posting to account for this additional release, but if you have locked your books and don't want to impact January's numbers, you can choose to update the January journal in February (by choosing a journal date in February) and this will create a second journal posting for January and create an adjustment line in the schedule so you will reconcile back to Xero. For more information on how the adjustment line works, see this helpful article. The net effect of this would be equal to $2,000 being released in February.