fix(freebusy): slot header format not respecting user's locale

Signed-off-by: Richard Steinmetz <[email protected]>

src/fullcalendar/localization/dateFormattingConfig.js

@@ -35,6 +35,7 @@ const getDateFormattingConfig = () => {
 				listDayFormat: 'LL, dddd',
 				listDaySideFormat: false,
 			},
+			resourceTimelineDay: defaultConfig,
 		},
 	}
 }