Calendar re-set wiped out all my events
When I launched Apple Calendar today it gives me a message "Updating Calendars". Apparently "updating" means it has wiped out all my current, previous and future calendar events. Is there any way to restore my old calendars? I couldn't find anything helpful in preferences. I tried syncing with my iPhone 6 to no avail. I'm afraid to trying syncing with my iPad for fear it will wipe out everything; the iPad has the most complete record of past calendars, so if push comes to shove I will manually transfer info from there to my calendar.
Or maybe I'll just switch to Google calendar. 😉
Thanks in advance.
MacBook Pro, OS X El Capitan (10.11.6), (15-inch, 2.53 GHz, 4 GB RAM)