Okay so I finally found my GameBoy with Pokemon Ruby in it after years of not knowing where it went and I decided to play it. After turning it on and getting almost to the main screen a message comes up that says this: "The internal battery has run dry. The game can be played. However, clock-based events will no longer occur." Just like it says I can play normally, nothing seems to be out of the normal. What clock-based events is it talking about?