Also posted here - https://extensions.xwiki.org/xwiki/bin/view/Extension/MoccaCalendar
How do I change the date format when creating or viewing an event?
It shows as dd.mm.yyyy - in US, we would prefer to use yyyy-mm-dd or mm/dd/yyyy.
Never mind. I didn’t see it before but I found the answer in the comments.
Answer: Go to …/xwiki/bin/view/MoccaCalendar/MoccaCalendarEventClass and modify the Start Date and End Date items in the class editor. The default is dd.MM.yyyy HH:mm - I changed to MM/dd/yyyy hh:mma for US-like formatting.