I def need to stress the gro clock does take time for some children to grasp the concept. But I found perseverance and reward charts for staying in their room till the sun came up worked here!
Now my 4 yr old who shares a room with his 2yr old sister has taught her to wait in bed or their room until the sun is up! I have a 15 week old that will get taught by his older bro and sis in time so it is a good investment!!!