Since 2006, the French Open has begun on a Sunday. The 2006 tournament introduced a 15-day schedule, making Roland-Garros the first Grand Slam event to start its main draw on a Sunday.
The change added an opening Sunday of singles competition, with matches spread across the tournament’s principal courts. Before then, the French Open traditionally began on a Monday, following the conventional 14-day Grand Slam timetable.
The Sunday start is not the same as the tournament’s opening-week activities. Exhibition events, qualifying matches, practice sessions and ceremonies can occur earlier, but the question refers to the beginning of the main tournament. The 2020 edition was an unusual exception in the calendar, taking place in September because of the COVID-19 pandemic, yet its modern scheduling tradition still traces back to the 2006 Sunday start.