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From Geohashing
Revision as of 14:55, 24 May 2008 by imported>Polysylabic Pseudonym (Saturday, May 24, 2008 - Saturday meetup)
Use this tool to find geohashing coordinates for a given area/date.
NoTerminal and Drache at the February 19, 2008 coordinates for Portland, Oregon

Welcome to the Geohashing Community Wiki. Geohashing is a Spontaneous Adventure Generator, brought to you by the xkcd webcomic. If you are already familiar with GPS and xkcd, then proceed onwards!

What is this?

xkcd comic #426, published on May 21, 2008, contains an algorithm that generates random coordinates around the world1 every day. Everyone in a given region gets the same set of coordinates. As such, these coordinates can be used as destinations for adventures, à la Geocaching, or for local meetups.

For a little more interactive discussion, consider joining the #geohashing IRC channel on Foonetic.

1. For time zone issues in Europe, Africa, Asia, and Australia, see 30W Time Zone Rule for an addendum to the algorithm rules.

How it works

Play with the coordinate calculator at http://xkcd.com/geohashing. All coordinates refer to the WGS84 datum.

Every day, the algorithm generates a new set of coordinates for each 1°×1° latitude/longitude zone (known as a graticule) in the world. They are randomly placed -- they could be in the forest, in a city, on a mountain, or even in the middle of a lake! You can use this wiki to document the daily coordinates (geohashes) you've been to.

Unless you can accurately predict the stock market, you can't figure out what the coordinates will be ahead of time. You can first calculate a weekday's coordinates at about 9:30am ET, and on Friday morning you can calculate the coordinates for each day that weekend (sometimes even through Monday when there is a US holiday).

When visiting geohash locations, please respect the area you are visiting. Absolutely do not litter or otherwise disturb the natural integrity of the area. However, if possible, creating some kind of a marker out of nearby materials (i.e. cairn of stones, blair-witch-style 'stick figures', etc.) is encouraged.

Disclaimer: When any coordinates generated by the Geohashing algorithm fall within a dangerous area, are inaccessible, or would require illegal trespass, DO NOT attempt to reach them. Please research each potential location before attempting to access it. You are expected to use proper judgment in all cases and are solely responsible for your own actions. See more guidelines.

Official xkcd meetups

Official xkcd meetups happen every Saturday afternoon at that day's normal geohash coordinates. All meetups start at 4:00pm (local destination time). If you go at these times, you might encounter other readers of xkcd. Bring games!

In such cases when it is unwise to attempt to access the generated coordinates, the Saturday meetup is postponed until a day when the algorithm provides a more suitable location. Alternatively, when the coordinates fall within a body of water, you can rent a boat and win the Water Geohash achievement.

Implementations

A full list of reference and practical implementations can be found on the Implementations page.

Active Graticules

Want to find geohashers in your local area? See Active Graticules for a list of graticules with active users in them.

Recent/Upcoming Expeditions

The coordinates for the Saturday meetup on May 31, 2008 will be published worldwide at 9:30am ET on Friday, May 30. See timeanddate.com for the Dow's Friday opening time in your local time zone.

Template:30w

Tuesday, May 27, 2008

The first day the 30W Time Zone Rule is in effect.

  • West of -30°: The coordinates will be announced at 9:30am ET on Tuesday, May 27.
  • East of -30°: The coordinates for Tuesday, May 27 are available. They were available early by combination of the Dow's Memorial Day holiday and the new 30W Time Zone Rule.

Monday, May 26, 2008

The coordinates for Monday, May 26 are available. They were available early due to the Dow's Memorial Day holiday.

Sunday, May 25, 2008

The coordinates for Sunday, May 25 are available.

Saturday, May 24, 2008 - Saturday meetup

The first Saturday meetup day since Geohashing publicly launched.

The coordinates for Saturday, May 24 are available. Convenient city graticules in the U.S. include: Madison, San Antonio, Cleveland, Portland, Rochester and Baltimore.

Friday, May 23, 2008

The coordinates for Friday, May 23 are available.

Thursday, May 22, 2008

The coordinates for Thursday, May 22nd are available.

Older Events

See the Expedition Archives for older events.

Known Issues

Several known issues are presented at Known Issues. There is an ongoing discussion on these and other issues at Talk:Main Page.

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