The method to expand all the events in Calendar View on load using Content Editor WebPart. You should add this code. You should copy and paste it to html file, save this file to document library and set its path into the settings of CEWP.

//Expand all the calendar events
function changeCalendarEventLinkIntercept()
  var OldCalendarNotify4a = SP.UI.ApplicationPages.CalendarNotify.$4b;
  SP.UI.ApplicationPages.CalendarNotify.$4b = function ()
function changeCalendarEventLinks()
//expand all

Yandex.RTB R-A-454402-1