title: Calendars show "NaN" instead of "June"
body: <p>Some owl-date-time calendars I'm using show &quot;NaN&quot; instead of June when implemented. I can't for the life of me figure this out, so at this point I'm just hoping someone else can tell me if they've had this bug before. Some of the calendars work and look almost identical, so any suggestions would be lovely.
  thanks in advance!</p>