Long story short we last-minute got invited to a wedding while we're on our trip to NYC.

Of course my first thought was what the heck do I wear. The invite had no dress code on it so I'm at a total loss.

Here's the details: It's on July 4th, ceremony at 3:30pm, reception at 6pm at a country club. I looked at the pictures of the country club, it looks pretty formal.

BUT since there were no dress code on the invite, I assume it isn't black tie or black tie optional. (I'm so bad at wedding etiquette!)

Here are my options:
The dress I wore to my wedding shower, it's a Maggy London.
https://www.facebook.com/photo.php?fbid=385090229689&set=a.385081604689.166243.720689689&type=3&theater

The dress I bought yesterday but not sure if I "love" or not:
http://www.whitehouseblackmarket.com/store/browse/product.jsp?maxRec=82&pageId=1&productId=570043817&viewAll=true&prd=Halter+Maxi+Dress&subCatId=cat210002&color=&fromSearch=true&inSeam=&posId=56&catId=cat4809277&cat=&onSale=true&colorFamily=&maxPg=1&size=

another option I tried on in the store and loved:
http://www.whitehouseblackmarket.com/store/browse/product.jsp?maxRec=45&pageId=1&productId=570049599&viewAll=true&prd=Palm+Leaf+Dress&subCatId=&color=&fromSearch=&inSeam=&posId=15&catId=cat210002&cat=Dresses++Skirts&onSale=&colorFamily=&maxPg=1&size=

HELP! I have to finish packing today!!