Liz has 2 clocks. Everyday, one clock is 20 minutes faster while the other clock is 30 minutes slower. Liz adjusts the two clocks so that they show the same time and comes back to check the clocks every 24 hours. How many days does Liz have to wait until she can see the two clocks showing the same time again?

**Note:** AM and PM don't matter as long as the faces of the 2 clocks are the same.