Syntax to pick up all periods after a sub var

Summary:

Do anyone have suggestions on how to pick up all periods after a particular period?

I.e. if an application has a December Year end and June is the current month, does anyone have any syntax so that all the remaining periods in the year get picked up. i.e. in this example Jul:Dec.

Where this could be useful is in an IF statement for the forecast months or a form.

RSiblings does not work and they are not all sibling, so hoping someone might have a clever solution.

Thanks