30W Time Zone Rule

There’s been a small change to the algorithm to deal with time zones. This change does not affect anyone in North/South America (excluding Greenland), does not affect Saturday meetup times anywhere, and does not change any currently known upcoming meeting times. The change:

For every location east of Longitude -30 (Europe, Africa, Asia, and Australia), 
use the Dow opening from the previous day — even if a new one becomes available 
partway through the day.

Put differently (the same functionally for everywhere except islands in the mid-Atlantic):

Consider any Dow openings published after noon local time 
to have occurred on the next day.

This is necessary to deal with time zone problems. For a lot of Europe, the Wednesday Dow opening was learned near sundown Wednesday, which meant they couldn’t use it to get to daytime meetups. For east Asia, they had to visit weekday locations the next day. A bunch of solutions were discussed, and I decided this was the cleanest.

A new version of the map program is being posted concurrently with this blog entry. The first coordinates that will be affected by it are Tuesday’s. Again, this does not affect anyone in the Americas.