How long do you have to recover?
You could look at it the other way around and design your programme and then create the ideal rest intervals.
But, in my view, the best approach is always to train as frequently as you can without adding additional stress (due to taking time away from the rest of your life).
So, if you can train every day, even twice or three times per day, so much the better.
Once you know how often you CAN consistently train, you know how long you have between your workouts. Therefore, you can plan the intensity of the workout as a whole.
For example, to make things simple, compare doing one workout per day to doing two.
If you designed one workout for the day, the start of that workout has your full attention, your highest energy, intensity and fuel level. But, as the workout continues, your strength and power will drop a little, as, most likely, will your focus.
Perhaps not by much, but it is fair to say that, if your workout lasted an hour, the return you will achieve from the first half of your workout will be higher than the second half.
But if you were to split the workout in half, doing the first half in the morning, rest, refuel and come back fresh for the second half, you will be able to give that half more intensity than you would have if it had come straight after the first half.
So, training more often does not necessarily mean doing more sets, it just means breaking them up with meals and recovery in between. Then, as you are better fuelled, there is scope to do slightly more in each ‘half’ than you would have had you done if combined in one complete workout.
For more on this, have a read at the article How Long Should You Workout?
Thus, if you were looking to squat every day, you need to do it to a level that you will have fully recovered by the next day.
Control the intensity
If you have done much training you will know that training to failure on an exercise, like squats, can often be with you for several days. Meaning you would not be able to work to true failure.
You may, however, be able to work to explosive failure. Continuing to lift until you start to grind the movement.
And, if you use a ramping technique (adding weight for each set) then your body will tell you when you are done for the day.
On day 2 you may not lift as much as you did on day 1 but that is just your body’s way of telling you it needs a little less thrown at it to recover in a 24hr period.
Simply listen, adapt and move on.
In the end, returning to the question at hand, it is in fact possible to squat every day so long as you are willing to either adapt to that rest period or face the consequences.
In truth, you CAN do whatever you want in the gym every day. You just might burn out or not get the results you wanted if you don’t listen to your body for feedback and make adjustments to suit.