"Empire Day" and "Gathering Forces" take place on Ezra's 15th birthday, since he was born on the day the Empire was declared in Star Wars: Episode III - Revenge of the Sith (2005). According to Pablo Hidalgo, Ezra is about two days older than Luke and Leia. This is the first episode set 15 years after Revenge of the Sith.
Tseebo has been fitted with the same tech headgear as Lobot in Star Wars: Episode V - The Empire Strikes Back (1980).
The march accompanying the Imperial parade is the "Imperial March" first introduced in "The Empire Strikes Back", transposed from minor key to major, with slight alterations.
There are various Clone Wars artifacts displayed at Old Jho's Pit Stop, including the nose cone of the Republic Gunship known as the "Crumb Bomber" in Star Wars: The Clone Wars (2008) and a phase one clone trooper helmet behind the bar. Several Pitt Droid heads are mounted on the wall to serve as lamps and a gunship engine serves as an overhead fan.