I have rewritten edit.php in /administrator/components/com_content/views/article/tmpl/edit.php to create an Events tab just like in this screenshot
The only main issues I'm facing is how to to Save these 3 (Start Event, End Event and Location Event). I've looked up in /administrator/components/com_content/models/article.php and yet to find a good example to follow on how to save into the database.
Need help how to save these 3 new input into #__content table database. And Yes, I have created 3 column for these 3 in table #__content