I would highly recommend against setting a review for analytics. Obviously it depends on what they're doing, but if you have to delegate time to reviewing numbers for a client, I'd have to wonder what they're actually doing.
Here's why: unless you're a data scientist or your job is to analyze the data from the collected analytics, that's something the client should do. If they're willing to trust your analysis, that's different, then fine. But if the client wants analytics set up and then decides that the numbers mean one thing but you think it means something else, then you're in for troubling times. I've dealt with this a few times and have given up on teaching clients on analytics because even with a degree in data science, egos get in the way. This number means this, that means that, and nothing you can say will change what they think. Not all clients will react that way, but depending on the type of work you do, many will.
Also, I don't know if you really want to spend the time reviewing analytics unless this is a long-term project and you want to use that data to determine future work. If that's the case, fine, but just be very careful with how you word the contract. That said, I'd suggest reviewing once a week for a total of 2 hours. In my experience I've spent a lot of time understanding the analytics data, but more importantly I'd bounce in and out of the reviewing when the need arose. So it was never an hour here and an hour there, but five minutes at a time, four times a day, etc.