Doug and Carrie's story line happens over two/more days while Arthur and Spence are in the shoe store the whole time.
Arthur and the shoe salesman reveal that they are WWII army vets, Arthur with the 71st Infantry Division and the salesman with the 29th. The salesman correctly stated that the 29th started action in D-Day but teases Arthur that they cleared the way for the 71st. In fact, the two divisions were never in the same corps. The 71st arrived in Europe in February 1945 and fought in southern Germany/Austria while the 29th at that time fought in central Germany.
As Doug and Carrie get to the church Lisa and Guy are getting into the limo apparently just after the ceremony but Doug and Carrie seem to think that this was the end of the reception because Doug makes the comment on how good the steak was. Everyone should really be heading to the reception.
King of Queens S3/E12 - At the very end when Doug and Carrie is running late to wedding, see a attendee (lady in red dress blowing bubbles) and when Doug goes to get into wedding posture 2 seconds later the same girl in red dress is there.
Over the end credits when Spence and Arthur are walking on the shore of the beach, a mountain range can clearly be seen in the distance. But on Long Island in New York there are no mountains visible anywhere from any of the region's many beaches.