Why doesn't the columnFormat of ui-calendar angularjs change?

Question

JavaScript

Hello everyone, almost everything has been done with the calendar (ui - calendar)
, only the day of the week the format does not change, can anyone come across such a problem?
Now the format is: "sun 1/2" in the form of fractions, I just want to remove this fraction, but it doesn't work (((
self.uiConfig = {
calendar:{
height: 1000,
defaultView: 'agendaWeek',
editable: true,
showWeeks: false,
header:{
left: 'month agendaWeek basicDay',
center: ' prev, title, next',
},
columnFormat: {
week: 'ddd', // <----------FORMAT ---NE--MENIAETSIA--------,
},
views: {
week: 'ddd',
}
}
}
I'll wait for an answer, thanks in advance