Turn Start Date into Pretty Date»
Once you've established a date, display it as you like (see catholic fdn single-events.php for complex usage)
ACF, PHP, WP/CP | Type: PHP
WP_query with Events Grouped by Month»
This is intriguing, but I've not tested it. Check the 2 links given with this solution.
ACF, WP Query, WP/CP | Type: PHP