I think I used to have the clock and the alarm time being shown on the upper part of my lock screen.
All of a sudden, since a couple of days ago, I'm now being shown the calendar on the lock screen.
If relevant, my device is a Samsung Galaxy Nexus.
On the lock screen swipe left so that there's a big + sign on the screen (or maybe another widget) and then scroll back to the calender so that it's now full screen. Long press the calender and drag it to the top of the screen to remove it.
On my phone the clock was automatically re-added to the lock screen after this but if it isn't then go to the lock screen, swipe till till you see a big + again. Click on this and from the menu of widgets that appears select the digital clock.
Long-click on the top portion of the screen with "calendar events", and it'll be possible for this screen to be removed.
Then the lock screen will show one of the leftover screens, which will likely have whatever lock screen was before the calendar lock screen.
Settings > Security > Notification settings Then uncheck what u want :)
I've also had this problem for the past few days and it drove me crazy. None of the things listed here worked.
However, I noticed I could slide the event screen to the right and the next screen was the clock that use to be my lock screen home page. I slid the screen back to the left and there was the calender event box. I held the top bar of the box and something red seemed to pop up at the top behind it. I slowly dragged the event box up into that red remove slot.
This successfully removed them from the lock screen.
