Hide the All Day and Recurrence Columns in SharePoint 2013/2016/2019

In a SharePoint 2013/2016/2019 calendar, there are some options that cannot be hidden through the GUI. Two of these are the All Day and Recurrence check boxes. But it can be done!

• Open SharePoint Designer to your site
• Go to Lists and Libraries, and open your calendar
• Under Content Types, click on Event.

• Under Customization, click on "Edit content type columns"
• Click on the column name you want to hide
• In the ribbon menu, click Administration Web Page

• In the web page, choose Hidden and click OK

Your column is now hidden, and will not show up in forms when your users enter an event.

Source: https://social.msdn.microsoft.com/Forums/office/en-US/7f39daf6-d88c-4271-8abc-80814e949a01/hide-all-day-event-and-recurrence-filed-from-sharepoint-calendar-in-sharepoint-2013?forum=sharepointcustomization