I figured it out! I had the same problem.
Go to your home screen and pull down the notifications bar at the top of your screen.
Click the Settings icon at the top right. (looks like a clockwork wheel)
Click the Personalize button.
Click the Lock Screen Style button.
Click the Settings button on the bottom left.
Uncheck the Display Calandar Events option and Check the Display Mails box. Then press Done.
In this way you can maintain the text notifications, but do away with the pesky calendar events such as Patriot Day. Even though you might actually be a patriot, you might not want a "patriot day all day tomorrow/today" notification.