Postagem original de: Dan ,
Check your clock settings when your laptop is not connected to a network after being turned off over night do you find the setting is getting lost? If so your settings battery needs to be replaced. The older generation of MacBooks and MacBook Pros used a small button cell batt to hold the PRAM settings and power the built-in clock. If your connected to a network via WiFi or Ethernet the clock will automatically reset to the Internet timebase which is why you must not let the system access it to check your button battery.