In short: the time you'll actually keep. Many Buddhists sit in the early morning, before the day starts, and briefly in the evening. The Buddha also said youth, good health and peaceful times are good times to practice, so don't wait (AN 5.54).
Questions people ask
Is morning the best time to meditate?
Many Buddhists practice in the early morning, before the day starts, and briefly in the evening. The best time is the one you can keep every day.