Wilde_Guess

Very useful, TBH… is something like.  https://www.timeanddate.com/moon/usa/portland-or  (change location & date/time for needs.  Glasgow UK should be close enough for Hogwarts.)

Thanks for the link.  I did find a different site that also works fine, once I remembered to actually check moon phases.  Unlike JKR herself, I’m trying to use real life calendars instead of the “Rowling Calendar.”  So, my student band would have been out late, plus the first Hogsmeade Weekend on Saturday, with Sunday being a full moon. 

Once I remembered to check that too, I got it fixed.  And though the dates are only background ephemera otherwise, I also moved one or two other Hogsmeade Weekends.  I also inserted a statement that even seventh year students were restricted to the castle on full moon nights, and that “student werewolves” never rode the Hogwarts Express out or in on a day with a full moon night.  In “expanded canon,” there were actually two students (Chiara Lobasco and Remus Lupin) who attended and took their NEWTs after having been infected with Lycanthropy as young children.

The real pain is finding stuff like when O and A Level results should come in, and minimum ages for drivers licenses, which did change over the years.

I find it useful when… you know, a character’s outside at night, to know about where the moon is (ie before/after moonrise/moonset).  Another tool I’ve used is Stellarium (open source program), good for figuring the constellations/stars in the sky.