Question: When To Exfoliate

When is the most beneficial time (for your skin) to exfoliate? I was told (by a professional) that night is best - which makes sense to me since it is at night that your skin rejuvenates and repairs itself. So to exfoliate at night will help the moisturisers and serums you use to penetrate and work better (my logic) not so? Recently I read that exfoliating in the morning is best. I haven't changed my practise of exfoliating at night. What would you tell a patient in terms of exfoliation and when to do it?