It Could Only Happen To A Writer

I just had one of those moments. I was looking at some of the background I'm preparing for NaNoWriMo and I noticed my MC was born June 22nd 2604. This happens to lots of people in Sci-Fi universes so it wasn't that big of a deal. Then I suddenly thought "probably a Friday".

This was one of those times to be glad I use Linux because the "cal" commandline utility can give a calendar for any year from 1 to 9999. I'm not sure how dependable it is before october 1582, but for the future it certainly works well. So I just ran "cal 2604" and wouldn't you know it: June 22nd 2604 is going to be a Friday.

Now I'm going to try to figure out how the heck my first instinct was right with only one chance in seven. Maybe it's because June 22nd 2317 is also a Friday, and I have a calendar from 2317 close at hand right now, for the edit of Gordian Knot.

Update: I did a little checking and cal is mainly questionable between October 1582 and September 1752. If follows the British Empire's dates for switching from the Julian to the Gregorian Calendar.