You were being asked: What is your offset for liability, if you only want to enter the liability now? That isn't really possible.

As I pointed out, Payroll Expense is a Gross event for the pay date. Gross = All. That means payroll math for the pay date is:

Total Expense, broken out by either Banking (checks issued as takehome) or as Liability (amounts to be paid out later). And Later, the rest of the Banking happens, as you pay out those liabilities.

And you stated "payroll was ran" at the end of the year, but you also stated it was Payable. Was it Paid to the employees with the pay date in Dec 2018? The date it hits their bank isn't the company's pay date. Examples:

You print checks dated 12/31/2018. That makes this Payroll for 2018, included in the 2018 941/944 reporting, in the 2018 W2, and Gross Payroll in the expense accounting. You also direct deposit, and that doesn't hit the employee bank accounts until Jan 2, 2019 (the next banking date for deposit); but the employer bank has the initiation date for 12/31/2018. That makes it part of the same 2018 year end payroll as the paper checks.

If you calculated what everyone should get, but didn't issue it until a Jan 2019 paydate, that makes it a January 2019 payroll.

And the liability pay date is not the Payroll date for expense; it's the Due Date for the banking, or you are considered late making that payment.