That's odd!
As far as I'm aware, Lotus Notes simply reads the date and time from the system clock. i.e. I can't see how Lotus Notes could have the wrong date unless your PC has the wrong date setting.
Place your mouse over the clock at the bottom right of your screen. This should show the current system date. If it's 30th October, I'm sorry I can't help. However, if it's 30th November, double-click on the time display. Change the month to October, then click 'Apply' and 'OK'.
Chris