It's a delight to see new faces here in the Community. Allow me to provide some information about processing payroll through direct deposit in QuickBooks Online.
You'll have to process and send your direct deposit payroll to Intuit at least two (2) banking days before the pay date, at 5 PM PST. This is the standard lead time given to move the money from your bank account to your employees' financial institution.
In your case, the pay date is on January 2nd, 2019 (Wednesday), the payroll must be approved by 5:00 PM PST on December 28, 2018 (Friday). However, since January 1st, 2019 (Tuesday) is a holiday, you need to transmit the payroll by December 27th, 2018 (Thursday).
For visual reference, I've added a screenshot with the Direct deposit workflow below.
You can also check out these articles for more details: