The field cache value MaxAge is set in the formatter, to let the system automatically refehsh the cache when a new opening or closing time starts. Tisis not yet properly done when today is an Exception day.
Active
1.23
Code - formatter
Issue #3512789: Fix field cache for exception day
The important line change is in CacheHelper;
foreach ($office_hours as $slot) { - $day = $slot['day']; + $slot_weekday = OfficeHoursDateHelper::getWeekday($slot['day']);
Automatically closed - issue fixed for 2 weeks with no activity.