With this episode taking place on July 4th, the series kind of book ends since the First episode of the series took place on July 4th.
During the 'fighting natural disasters' footage shown on WatchTower screens, Green Arrown and Black Canary can be seen helping students exit a school bus on a bridge. This is possibly un-unused footage from the 1st season's 14th installment, since, as in that segment and the prior one, the bus is marked Metropolis School District, and GA & BC usually operate in Star City.
The pan shot of all the heroes listening to Lex Luthor was a difficult and took a long time to get the shot right. It used a lot of the characters and none of them were moving except Bumblebee's wings.
The events depicted occur on June 20th, and July 4th and 5th.