Advance tax due date for fy 2010-11

Dear Members,

Will anybody knows that the last date for advance tax installment in March was extended to 31st march 2011 from 15th March 2011. If  Yes can provide me the notifications issued in this regards. 

And if such date was not extended please clarify me. I have a doubt regarding the extension.

Thanks in advance...

Sanjay Verma