This morning we received an email saying that the US embassy would be closed on August 4th. After reading this email, I checked the New York Times, to find that this closing was not simply scheduled for Oman, but several other middle eastern countries such as Libya, Kuwait, Saudi Arabia etc. Here is an article that explains the issue in more depth.
On a side note, this morning I took a cab back from the LuLu supermarket to our apartments. The cab driver and I agreed upon 200 baiza but when we arrived to my destination he said in Arabic "it's free. Thank you." My first thoughts were "why is he driving me for free?" and "why is he thanking me?". Before coming to Oman, people told me things like this have happened, but I never thought it would happen to me!