Google’s online calendar has removed default references for a handful of holidays and cultural events — with users noticing ...

In a statement emailed to USA TODAY, a Google spokesperson said, "For over a decade we’ve worked with timeanddate.com to show public holidays and national observances in Google Calendar.

Although it sounds weird, the date and time settings could be the reason for your Calendar-related issues. If you don’t set them correctly, Google’s servers might have trouble syncing with them.