Hi Matthew,you might solve this using "custom time entities".In that specific case you could create another year entity above Month which then is only linked to december (and rest to "_").https://www.boardmanual.com/2021/summer/data-modeling/2_Database_design_functions/7_Time_Range/the-time-range-section.htm?rhsearch=time entitiesIf it is just relevant in screens you might also work with pagers on month and selection on year.
In that case you could define the "period" of the pager with "last period":Kind regards,Bettina