Why does the US Open start its tournament on a Sunday?

For the first time in its history, the US Open will begin not on Monday but on Sunday.
With this decision, it becomes the third Grand Slam to extend the duration of its tournament, increasing from 14 to 15 days. The 2025 edition will therefore start on Sunday, August 24 and end on Sunday, September 7.
Roland Garros was the first Major to make this change (in 2006), followed by the Australian Open in 2024. A decision largely motivated by financial aspects. Indeed, more days mean more attendance and therefore more money.
Consequently, Wimbledon remains the last tournament to start on a Monday and run for only 14 days.
It is worth noting that the English tournament has also made history by changing the schedule for the middle Sunday of the fortnight. Historically a rest day for players, it is now part of the program.