McDonald's typically starts serving lunch at 10:30 a.m. local time from Monday to Friday. On weekends, the lunch start time can vary slightly, usually around 10:30 a.m. to 11:00 a.m., depending on the location. This is generally when the restaurant switches from the breakfast menu to the lunch menu. The exact time may vary by location, so it's a good idea to check with your local McDonald's for precise hours. Lunch service usually runs until closing, which for some locations is as late as 11 p.m. or even 24 hours for certain outlets.