We are arriving from the US in Edinburgh in mid September on a Sunday (mid-day). Can we expect to still get some sightseeing or shopping done or will attractions and shops most likely be closed? Just trying to plan our itinerary ahead of time as we will only be spending two days there. Many thanks!

You should be OK - shops are definately open (I live there) and I think most of the attractions are too.

As Keith said you will be fine. Shops definitely will be open...just not as long. Close around 5 or 6 or something. I'm sure Edinburgh Castle and some other attractions will be open as well. Check out their website.
Have fun!

The open-top hop-on-hop-off tour buses will also be running. So if you are really jet lagged/tired (likely after an overnight and connecting flight), it would be a good way to get your bearings, be out in fresh air, and not have to do anything too strenuous.

We arrived in Edinburgh mid-morning on a Sunday this past February. We were able to leave our bags at the hotel (couldn't check in yet due to a large Six Nations rugby crowd), and set off on foot. We toured Edinburgh Castle, the upper portion of the Royal Mile, and ended up at a pub on Rose Street to watch the latter portion of the Scotland / Ireland rugby match. (We had an added bonus of seeing thousands of male Scottish rugby fans decked out in kilts and Famous Grouse jerseys...) Everything was open -- shops, museums, the Castle and the Palace. Have a great time!

SugarPlum, that sounds like an ideal first day!

Thanks for sharing to all the posters that answered my question.

I have to say Janis's suggestion worked wonderfully for us...we were extremely tired, had been up well over 24 hours, but wanted to make it at least until the evening...got on the open top buses for a tour and it was the BEST--did the same thing the next day but knew where we wanted to get off and on, etc...highly recommend!