Yu Lan is a Buddhism originated and Chung Yuen is Taoism originated. Yu Lan is remembering Mu Lian who want to safe his mother. Advised by Buddha to do offering on Chinese calender 14th July.
Same goes to Chu g Yuen festival where 14th July of the Lunar calender is a day when the hell’s gate open and allow ghost from the hell out to the world.
The cultural differences may be vary over the ways to celebrate the day. We are not sure if there is any relation towards multiverse concept. However, the similarity of both Taoism and Buddhism linked the same day with a purpose.
Although we do not believe in Buddhism, Taoism, confusiousm, or even capitalism that lead to burning of modern gadgets for the spirits. The same date that linked both culture together on this date is questionable.