G0180 item 24 a

Please clarify on the usage of G0180. In HIPPA 1500 form the ITEM 24 A states from Date of service - to date of service.

For example the claim form states in ITEM 24 A as 09132011-09172011-G0180 with fee 50$ and quantity as 1.

In this case please clarify me the DOS for CPT® G0180...?