<p>I always recommend a maximum of 20 minutes at a time (the only exception is when taking a full practice test). Breaks should be as long as possible. For example, if you want to study for an hour a day (which is a lot), then I suggest 20 minutes in the morning, 20 minutes in the afternoon, and 20 minutes right before bed.</p>
<p>If you have 4 months before your next SAT, then one 20 minute study session per day is enough. If you only have 1 month, then 3 times would be better. </p>
<p>You can study more than 3 times a day if you wish, but try to follow the general rule - space out the sessions at equal intervals so that they are uniformly distributed throughout the day. This will optimize the effectiveness of your study sessions.</p>