User blog:Ironyak1/Time is making fools of us again - Calendars in J. K. Rowling's Wizarding World

In working through each book to better understand the timeline of events in J. K. Rowling's Wizaring World, two facts have become clear to me. One - Rowling has mapped out many of her events quite meticulously, fitting dates and days of the week into a very complete and cohesive calendar. Two - that calendar most often bears little to no relationship to the real world calendar for that year.

As is well understood within the Fandom, the Harry Potter timeline was originally established around one primary date - Nicholas de Mimsy-Porpington 500th Deathday party, which celebrated the anniversary of his death on 31 October 1492. From this date, the events of could be deduced to have taken place starting in 1992 and given other peoples' ages, birthdays, and various temporal details, a whole rich timeline could be established.

Much of this work was done by Steve Vander Ark and the other contributors to the Harry Potter Lexicon. Working from evidence given in Rowling's writings and interviews, and working with the real world calendar for the given time period, the HP Lexicon was able to build complete calendars for each of Harry's school years, and timelines for other historical events in the Wizarding World. Some of these Calendars were used by Warner Bros. in developing the films and even appeared as sanctioned extras on the DVDs.

However, trying to fit these events into the real world calendar was often problematic as days of the week given in the text do not line up with the actual day of the week on the calendar. While the Lexicon would often add or remove a day to help correct for these mis-alignments, see Calendar for Philosopher's Stone many times the days of the real world calendar would be used over the days given in canon, leading to oddities such as students taking classes on the weekend (see 14 February from Chamber of Secrets Calendar or 16 October from Prisoner of Azkaban Calendar).

In reviewing many dates and days of the week as given in Rowling's writing, it becomes clear that although the events are supposed to occur during a given year, her days of the week almost never align with the real world calendar (RWC):


 * 1 November 1981: JKR = Tuesday, RWC = Sunday
 * 31 July 1991: JKR = Tuesday, RWC = Wednesday
 * 14 February 1993: JKR = Day of week with Charms, RWC = Sunday
 * 16 October 1993: JKR = Friday, RWC = Saturday
 * 6 June 1994: JKR = Thursday, RWC = Monday
 * 31 August 1994: JKR = Sunday, RWC = Wednesday
 * 30 October 1994: JKR = Friday, RWC = Sunday
 * 24 November 1994: JKR = Tuesday, RWC = Thursday
 * 12 August 1995: JKR = Unknown, but MoM seems busy for a Saturday, RWC = Saturday
 * 2 September 1995: JKR = Monday, RWC = Saturday
 * 14 February 1996: JKR = Sat (or Sun), RWC = Wednesday
 * 18 June 1996: JKR = Thu/Fri, RWC = Tuesday

Her dates however are most often consistent within themselves for each book, at least over the short run. Setting 16 October 1993 on a Friday, when Lavender Brown learns of the death of her rabbit Binky, leads to a Saturday 31 October, when the third year students first visit Hogsmeade. The posting of notice for the Triwizard Tournament on Friday 30 October 1994 results in the 24 November being a Tuesday, which is stated as the day of the First Task. This carries over to 24 February, the date of the Second Task, which is implied to be a Wednesday which again is consistent. It even extends to 24 June, the date of the Third Task and the last day of exams, being a Thursday, which is the last day of exams in previous years.

Note however that not all years are quite as consistent, especially when several months at a time are considered. In, 2 September 1995, the first day of class, is set on a Monday. However, this would lead to 14 February 1996 being on a Friday, whereas it is actually the Hogsmeade weekend setting for Cho Chang's and Harry Potter's first date in the book. Working from other dates, it's clear that Rowling was often working from a calendar, as seen here, but not from the real world calendar and also took some liberties on placing dates.

In she finally does align a date and day of the week with the real world calendar. 1 March 1997, Ron's birthday, falls on a Saturday in both the book and the real world calendar. Moreover, 2 September 1996, the first day of classes, is implied to be a Monday in the book and also falls on a Monday is the real world calendar. Whether this consistency over several months of events is evidence of her working from the real world calendar by this time in her writing, or just a fortuitous coincidence, is not clear.

Of course, given Rowling's infamous and oft-cited difficulty with math sometimes, she does have her more grand mis-steps as well, such as having two Mondays at the beginning of term. It is stated that the Weasley family are preparing on Sunday for the Hogwarts Express the next day, then travel to Hogwarts the next day (Monday), and then start classes the day after which is also Monday. While the rest of the dates for the book are well structured and consistent, this oddity is hard to explain away, even with magic.

Overall, there is plenty of evidence that Rowling laid out many of her events in a very structured manner. However, in reviewing the specifics of the dates given, it becomes increasingly clear that the calendar from her world most often does not align with the real world, and attempting to use the real world calendar to deduce and assign dates in her world will many times lead to inconsistencies and direct contradictions with the canon she has established.

TL;DR Rowling's dates and days of the weeks are often well structured and are internally consistent, but almost always do not match the real world calendar. Building a timeline for events in the Wizarding World should be based on Rowling's stated canon first and foremost, and not on trying to reconcile or force her events into the real world calendar creating obvious inconsistencies and direct contradictions.