iCloud Calendar won't let me enter correct times

I am running on OS X Lion (until I decide to upgrade Parallels--ugh) and my employer is on Yosemite (or Mavericks--can't remember). In the last week or so, whenever I add events on my laptop to her Calendar on iCloud, certain times will not stay input as I enter them: 2pm reverts to 1pm, 3pm to 2pm, etc. until I get to 8pm when it stays as I enter it. It's really WEIRD! So far, the only workaround is to find a previous event with the same time and edit the event and date--which is cumbersome and a pain in the butt! I've checked her iCloud preferences and the time zone is correct. Also, I can add it correctly from her laptop, just not mine. And I can add correctly to my own calendar. HELP!!!!