In days of old, the day was believed to begin at sunset. Therefore, to put this in modern perspective, the day of the festival was thought to have already begun on the evening of the previous day; and this was called Yoiyama, or procession eve.

Procession eve is the time during the Gion Matsuri when flames are lit in the decorative komagata lantern of each Yama-Hoko, who in turn are beautifully decorated with figures, tapestries and metal ornaments. The voice of the children dressed in yukatas singing songs meant to act as protection charms can be heard throughout the festival. It is the time in which the festival spirit reaches its climax. The Early Festival (Saki Matsuri) on the 16th and the Latter Festival (Ato Matsuri) on the 23rd are the actual dates of Yoiyama, however in recent years the Early Festival (Saki Matsuri) has begun to last from the 14th to 16th while the Latter Festival (Ato Matsuri) - from the 21st to the 23rd. 
 

July 14～16	Early Festival Yoiyama The flames are lit in the decorative komagata lantern of each Yama-Hoko and the Gion Music from the floats fills the air. The pedestrian roads and the floats themselves are gorgeously decorated with festival lanterns. Old houses in Yamahoko-cho remove the latticework from the front and open their tatami rooms to the public, where they display their treasured folding screens and other decorations.
July 17, 9 a.m.	Early Yamahoko Junko (Float Procession) The procession of 23 floats is demonstrated along Shijo, Kawaramachi, and Oike streets. Their beautiful decorations appear even more splendid under the bright summer sunlight.
July 21～23	Latter Festival Yoiyama The flames are lit in the decorative komagata lantern of each Yama-Hoko and the Gion Music from the floats fills the air. The pedestrian roads and the floats themselves are gorgeously decorated with festival lanterns. Old houses in Yamahoko-cho remove the latticework from the front and open their tatami rooms to the public, where they display their treasured folding screens and other decorations.
July 24, 9:30 a.m.	Latter Festival Yamahoko Junko (Float Procession) The procession of 11 floats is demonstrated along Oike, Kawaramachi and Shijo streets.