If the company requires to get start before the date when my EAD is effective, say, my EAD is not valid until mid October but the job needs to start no later than the end of August. Is there any way to get around this problem?

My situation: I already got my EAD (but not effective yet) and was approved for graduation, so I don't think there's anyway to get a CPT. The company is a huge international company and I'm not sure if they would let me volunteer working for one and a half months.

Thanks in advance.