I need to add PTO time on Dec 29 but the dates are "greyed" out and not available

Welcome to the QuickBooks Community, Cassel. I'll put you in touch with our best help available so you can apply Paid Time Off (PTO) hours to last year's dates in QuickBooks Time (QB Time).

Before doing so, we can perform some workaround for the time being by modifying the accrual settings. I'll show you how:

1. Go to Feature Add-ons and select Time Off Codes.
2. Choose the time off code you want to edit and click the pencil icon to edit.
3. Check the Track Accruals box and select Edit Settings.
4. Change the Accrual Settings to None and uncheck the Use it or lose it box.
5. Click Apply, then Save.

If the issue persists, I recommend reaching out to our QB Time support. They have access to a screen-sharing tool that will help diagnose the problem and walk you through the resolution. They may also raise an investigation regarding this matter if necessary. 

Furthermore, your team members can access the QuickBooks Workforce to submit time off, view the status of previous requests, and check their balances.

Let me know in the comments below if you have any clarifications about applying PTO hours. I'll be happy to return to this thread to assist you further. Take care, and have a good one.