You can create each event as a ‘public holiday’ so that the events would appear in the calendars of employees.
Go to eLeave > Leave Setup > Public Holidays.
After which, select list view > Edit > add new holiday
Employees would not be able to apply leave on those days as the system will deem them as non-working days.
However, if you are also using the eTimeclock module, this may cause additional OT/pay difference. So you should only do this method if you are not using timeclock as well.