The Devdas star arrived four hours late at an event in New Delhi, prompting complaints from journalists.
When asked whether his punctuality might ever improve, Khan said: "No! Actually I would like to, but you know what happens... I am right now in the middle of a lot of work. So I slept at 11 in the morning and I need to sleep a couple of hours. So I really apologise... Mujhe maaf kardo (Please forgive me)."
The 45-year-old promised to inform his organisers and the media about his delays.
At a recent event to announce his collaboration with YouTube for RA.One, Khan reportedly arrived three hours late, and at a Nokia event in Mumbai he made the media wait for over two-and-a-half hours before turning up.
The actor is currently promoting Ra.One in India.
Watch the trailer for Ra.One below: