Hi @sdetweil @MMRIZE
This used to be possible before, but after implementing the weather icons, it stopped working. It’s not a big deal but it’s a nice to have feature.
As you know, MagicMirror uses a very old version of Font Awesome. I updated mine to the most recent version and it now includes the Canadian flag and many other brand icons. Unfortunately, for brands, you have to use “fas” or “fa-solid”, and for brands you have to use “fab” or “fa-brands”. I solved this by tweaking the code in calendar.js and config.js. I also tried to do the same in MMM-CalendarEXT3.js, line 242, but when I try to update config.js calendar module, the calendar shows no data. The reason, because MMM-CalendarEXT3 module does not accept spaces in symbol.
CalendarEXT3.js, line 242:
symbol.className = "fa fa-fw fa" + s;
config.js, for birthday calendar
symbol: "s fa-cake-candles",
config.js, for Canadian holidays
symbol: "b fa-canadian-maple-leaf",
The space breaks my code, I wanted to choose either “b” or “s” in the symbol field
How the icons look in the native calendar

Unfortunately, not allowing spaces, forces me to decide which one to use or “fas” or “fab”
