calendar year match true up, off calendar year plan

Starting in 2018 the plan instituted a required match on a payroll basis with a true up contribution to be funded each year.  This matching true up computation period is on a calendar year basis.  The plan is an off calendar year plan with a PYE of 9/30. The match true up was calculated based on the 2018 calendar year and the computation period crossed over two different plan years and was funded during PYE 9/30/2019. 

We are pulling year end census data including matching contribution data for plan year end testing and were questioning how  to best include the match true up for testing.

Is it appropriate to Include it as a contribution made in the PYE 9/30/2019 even though the computation period was over parts of two separate plan years?

looking to see if someone else might have run into this before and how they handled it.