Those schedules are a matter of operational security, and are not released to the public, nor should they be.
you leave and go to a different island
After you get the Island Medallion, or anytime you want to leave the island, use the time device at the "LAB" setting, which takes you outside Pendulum's Lab in the "present". Then you can leave Main Street as usual in the blimp.
You leave the island the same way you returned to the future the second time, by using the Lab setting to return to the "present time", outside Pendulum's Lab.
After you travel back to the future to get the Island Medallion, return to the present to leave the island (just as you did after completing the items), by using the Lab selection on the time device.
You can leave any time by using the time device to go to another time.
"tomorrow", an adverb of time.
The duration of This Time Tomorrow is 2700.0 seconds.
This Time Tomorrow was created on 2008-07-05.
This Time Tomorrow ended on 2008-08-23.
No Time Like Tomorrow was created in 1959.
"What time is our meeting tomorrow?" is acceptable grammar.
To leave Time Tangled Island, click on the time device on the bottom left of the page, and select "lab". This will take you outside Pendulum's Lab on Main Street, and you can take the Poptropica blimp. If you have the Haunted House card in your Store Items (free), you can leave Time Tangled Island or Astro Knights Island without returning to Main Street : select Use on the Haunted House, then immediately leave and you will reach the islands map. (*leaving space on Astro Knights parks your spaceship on top of the castle)