Anybody understand this NOTAM?

!BDR 02/020 JSD CGSA WEF 0602111200-0602112100

Duats can't translate the CGSA:

Stratford CT (Sikorsky) [JSD]: February NOTAM #20 issued by Bridgeport CT
[BDR]:
CGSA effective from February 11th, 2006 at 07:00 AM EST (0602111200) -
February 11th, 2006 at 04:00 PM EST (0602112100)

I'm assuming it stands for Class G Surface Area, but what the heck does
that mean? Is this just some cryptic way of saying the tower is closed
during those times?