Determines the text that will be displayed on the calendar’s column headings.
format string, default:
'ddd' // like 'Mon', for month view 'ddd M/D' // like 'Mon 9/7', for week views 'dddd' // like 'Monday', for day views
As noted above, each view has a specific default. Get fine-tuned control with View-Specific Options. A single string alone will set the value for all views.
The default values will change based on the current locale.
This setting was renamed from columnFormat in version 3.8.0