Documenting Emergency Room Date of Service

When a patient comes into the Emergency Room at 11:30pm on 1/1/15 and is not seen by the resident/attending until 2am on 1/2, our residents are documenting the date of service on their ED notes as 1/2 which is the date services were rendered. We bill the professional side only and the date of service on the claim is 1/1 but if the documents are requested, they are dated 1/2 so some insurances are denying these as incorrect dos. We have asked our docs to document dos as the date the visit started and they refuse saying that is misrepresenting their services. Has anyone else come across this? and what is the solution?

Thanks!

Documenting Emergency Room Date of Service