The amount of time you should dedicate to revision for Commerce depends on various factors such as your current understanding of the subject, the complexity of the topics, and your personal study habits. However, a general guideline is that you should allocate enough time to thoroughly review and understand the key concepts and principles in Commerce.

It is recommended to create a study schedule and allocate specific time slots for Commerce revision. This schedule should be realistic and manageable, considering your other commitments and responsibilities. You may want to break down your revision into smaller, focused sessions rather than cramming all at once.

Additionally, consider incorporating active learning techniques such as practicing past papers, solving case studies, and discussing concepts with peers or teachers. These methods can help reinforce your understanding and improve your retention of the subject matter.

Remember that everyone's learning pace and requirements are different, so it's important to find a revision routine that works best for you.