All Calendar functions gone

[iMore Question]

Dear Apple,

Since Yesterday all my calendar functions are GONE. All appointments are gone, can't make new ones, nothing. Obviously a disaster. What could be the cause? Ed Eringa.

 

[sting7k]

Do you sync your calender with any calender services? Such as Google, iCloud, or Outlook?

 

[Just_Me_D]

Dear Apple,

Since Yesterday all my calendar functions are GONE. All appointments are gone, can't make new ones, nothing. Obviously a disaster. What could be the cause? Ed Eringa.

In addition to what Sting7k asked, what Apple device(s) are you using? Mac, MacBook, iPhone, iPad? What calendar app are you using? Native or third-party?