Show entries within a date range (start/end dates), filtered by day of the week using Craft CMS
{% set startEndEventsInRange = craft.entries.section('events').type('eventWithStartEndDate').startDate('<= '~today | date("U")).endDate('>= '~today | date("U")) %}
{% for event in startEndEventsInRange if event.daysOfTheWeek.contains(weekday) %}
{{ event.title }}
{% endfor %}
Requires date fields for the start date, end date and checkbox fields for the days of the week. The variable weekday refers to:
{% set weekday = today | date("l") %}