ACH transfers are processed first thing in the morning on the payday date.
However, it is important to note that ACH transfers can have longer wait times to complete. While it is normal for the transfers to land in the morning, the exact timing can vary depending on the bank. In general, regional banks can take longer to process than national/global banks.
If the payroll was expedited (i.e. Next-day pay) or a 4-day processing period over a holiday, it would be expected to arrive by EOD.