The best time for meditation is in the early morning as the mind is clearer and sharper then and not yet distracted by the day’s activities. Familiarizing yourself with wholesome thoughts and emotions in the morning influences how you live the rest of the day.
This is especially if you generate bodhicitta, which opens your heart to all sentient beings, and remember that people and things are transient and lack an independent nature, which reduces your grasping. If your schedule doesn’t permit you to meditate in the morning, meditate at another time in the day when you can relax and will not be interrupted.
Although meditating for an hour is good, if that is not possible, do what is comfortable for you. Conclude before you feel tired so that you will have a positive feeling about meditation. Pushing yourself to meditate for longer than you are comfortably able to will make your mind resistant to future practice.
Ten minutes of good-quality meditation is better than sitting for an hour with a distracted or sleepy mind. However, a person who is very busy and has little fortitude will find meditation almost impossible. He should do just a short prayer and then finish. That’s best.