Purchase Orders - Force future dates at year end?

Good morning,

At year end, we have a cut off date for purchase orders to be placed, say December 11, 2017.  After that, we would like all orders to have dates in 2018.  We enter purchase orders manually - no EDI or electronic uploads.  As you can imagine, manual entry results in errors and dates that are still in 2017.  Is there a way to force the Order and GL Dates in purchasing to start in 2018?  I've looked at the processing options for P4310 but nothing jumps out.  We're on E1 9.2.

Any and all ideas are welcome and appreciated.

Thank you,

Rachel