selfUpdate () {
		const ONE_MINUTE = 60 * 1000;
		setTimeout(
			() => {
				setInterval(() => {
					Log.debug("[Calendar] self update");
					if (this.config.updateOnFetch) {
						this.updateDom(1);
					} else {
						this.updateDom(this.config.animationSpeed);
					}
				}, ONE_MINUTE);
			},
			ONE_MINUTE - (new Date() % ONE_MINUTE)
		);
	}
Refresh the DOM every minute if needed: When using relative date format for events that start
or end in less than an hour, the date shows minute granularity and we want to keep that accurate.
--
When updateOnFetch is not set, it will Avoid fade out/in on updateDom when many calendars are used
and it's allow to refresh The DOM every minute with animation speed too
(because updateDom is not set in CALENDAR_EVENTS for this case)