You get 6 Leves per day. Maximum of 100 Leve Allowance. It's very generous if you indeed do like to do them.

The Allowance is to keep powerleveling in check. As it is, people already massively abuse them for leveling crafting classes far quicker than SE had initially intended them.

If you want to do all a boatload of them at once, you should wait like 16 days. That will get you 96-99 Leves you can do (depending upon when your Leves roll over).