calvin peters 10/29/2019 12:59:41 PM
If you're trying to compare current month to last month results would it not be something more like
Show Difference: FirstDayOfMonth([SomeRefColDate])=FirstDayOfMonth(AdjustMonth(Today(),-1))
I use something like this in a header to project a rolling total This year-over-Last year.
Not sure if that answers your question or not but it doesn't require a rel'n or knowledge of a largest Record Id. Just date ref's.