Which date for H1B renewal ? ( visa expiration date or I-797 date )

[prashanthchou]

I need to go for H1B renewal to Canada.

My Visa in the passport expires on Nov '05 and my I-797 expires on Jun '05.

Now for me to go for H1B renewal stamping which date should I consider ?

June '05 or Nov '05.

I have gotten my new I-797 also which starts from Jun '05 to Jan '07.