Question on STEM Extension

[arjhr]

Hello,

My OPT details are as follows -

Pre-Completion OPT-

Start Date - 10/1/2012

End Date - 12/30/2012

At 20hrs/week.

Post Completion OPT -

Start Date Applied for - 12/31/2012

Start Date on EAD Card - 1/16/2013

End Date on EAD Card - 10/14/2013

As per my calculations, the post completion OPT must run from 12/31/2012 to 11/14/2013.

My question is, is my university allowed to adjust for these dates when I apply for my STEM extension? Or would I have to reapply and get my current OPT expiration date changed by filling out the I765 form again?

I appreciate responses.

Arj