Does 2010年10-12 means October to December of 2010, or October 12th, 2010? I want to know whether 2010年10-12 indicates a range or an specific date.
In that case it would be saying 10th month through 12th month

See @Ming's comment about the specific date format.

There could be a case where the writer is using their own unique format, but that would depend on context