The Ghost Festival, also known as the Hungry Ghost Festival is a traditional Buddhist and Taoist festival held in certain Asian countries. According to the Chinese calendar, the Ghost Festival is on the 15th night of the seventh month.
In Chinese culture, the 15th day of the seventh month in the lunar calendar is called Ghost Day and the seventh month in general is regarded as the Ghost Month, in which ghosts and spirits, including those of deceased ancestors, come out from the lower realm. Distinct from both the Tomb Sweeping Day and Double Ninth Festival in which living descendants pay homage to their deceased ancestors, during Ghost Festival, the deceased are believed to visit the living.
On the 15th day the realms of Heaven and Hell and the realm of the living are open and both Taoists and Buddhists would perform rituals to transmute and absolve the sufferings of the deceased.
See the photo of food offerings for the Ghost Festival from Sonygood!
Reference link: https://en.wikipedia.org/wiki/Ghost_Festival