Option for Second Alert on Calendar Events Disappeared After Mojave 10.14.6 Update I just updated my Macbook Pro to Mojave 10.14.6 and noticed that I can no longer set a second alert on events I add to my Calendar. I'm not using any external calendars or accounts, just my iCloud. I can still set second alerts on my iPhone, just not my computer.
Depends what is your default calendar settings. If you select iCloud Calendar then you will have plus sign option next to the alert.