Thanks @sdetweil!
So it’s the call to moment.calendar() as you suggested. I changed calendar.js (line 339) to pass in a customised format:

calFormat = {
	sameDay: 'LT',
	nextDay: 'ddd[,] LT',
	nextWeek: 'ddd[,] LT',
	lastDay: '[Yesterday]',
	lastWeek: '[Last] ddd',
	sameElse: 'DD/MM/YYYY'
};
timeWrapper.innerHTML = this.capFirst(moment(event.startDate, "x").calendar(null, calFormat));			

Presumably I could easily pull that format in from this.config?

@sdetweil said in Calendar: Change format of relative times/dates:

dateFormat: “MMM Do”,
dateEndFormat: “LT”,
fullDayEventDateFormat: “MMM Do”,

Thanks @sdetweil, I appreciate the speedy response! I have given that a go but they don’t affect the “Monday at 07:00” at all?

I’d like to change the relative time format for Calendar entries from (e.g.) “Monday at 07:00” to “Mon 07:00” or similar. I’m using the standard “calendar” module.
I’m using a small screen (Raspberry Pi touch screen) with MagicMirror and so have very limited screen real estate. As shown below, the “Monday at 07:00” takes up a good chunk of space, so I’d like to make the column as compact as possible…
I’ve fiddled with various config entries but can find nothing that controls the “Monday at” part of the text.
Any ideas?