Usually if you have done a full fledged reading for 1 hour then you do not need a reading for atleast 5 years. Untill and unless something new comes up, you have some new questions in your mind etc etc and you are very curious to get answers then its a different case. But i always suggest my clients do not do readings frequently if you have already done it in detail be it with me or with any other reader before.
So if you are someone who needs clarity frequently, then i would recommend you can do it once in a year or so, not more that. This too if its very important and you want to know the current energies of the other person or what are they thinking about you, then its a different case. What does the other person think about you is something that be be found even 10 times a year. Every reader is required to do proper pre shuffling and energizing of cards for the client before the actual reading is going to take place. That process takes 30 minutes to an hour sometimes, it all depends on the number of questions that the client have. Its very difficult to pick up energies frequently for other major subjects if you do readings every 6 months. So i would suggest you to wait for atleast a year before you do another reading in case of an emergency. This also gives the querent enough time for the reading to play itself out.