I think they can visit the Date Place when they're six years old. It might be sooner, not sure. Tamagotchis age while they're sleeping. There's a trick you can do to make the Date Place appear sooner that involves setting the time on your Tama to one minute before they wake up. Everytime they wake up, their age counter increases. The Date Place appears when they're six, so just set the time to one minute before they wake up, let them wake up and then check to see if the Date Place is there when the age counter says they're six. I'm pretty sure they still need to have been adults for two days in order for the trick to work. The trick only worked on my Friends when they were four before doing the trick. Also, if you pause your Tama, it won't age.