If deferrals have delayed effective date of 7/1, but ADP Safe Harbor Match has no Delayed Effective Date, what compensation is used to calculate match?

A new 401k plan is adopted in March 2024 with deferrals effective 7/1/2024, but all other provisions, including the SH Match provisions, have no delayed effective date.  I am probably overthinking this, but logic tells me that compensation paid in the period before the employee could even make deferrals (1/1/-6/30) would not be counted when calculating the match.  Since the match is tied to the employee deferrals, is there any situation where the IRS would include the compensation before the effective date of deferrals in that SHM calculation?  

Thank you

Plan document will have that spelled out, whether the match compensation is determined on the whole year, pay period to pay period, and/or only from one's participation date in the source.