worldKit supports time navigation. Many processes investigated with GIS have a significant temporal dimension: urban planning and land use, hydrology, fires, ecological change. In addition to being spatially arranged, controls allow annotations to be revealed according to their timestamp. Looking at examples probably does a better job of explaining: History of Urbanziation and Tower Hamlets.

Annotation timestamps for an <item> can be set in subtags: <dc:date> in RSS 1.0, <pubDate> in RSS 2.0, and <updated> in Atom. Most weblog systems will include publication date in feeds automatically.

The format for <pubDate> is defined here, and basically looks like this example:

The format for <dc:date> and <updated> is defined here, and basically looks like this example:

worldKit adds a time navigation control to the bottom of the map. Moving the slider reveals all points occuring before that time. There are also key controls: "p" to Play, "r" to Rewind, "s" to Stop. The configuration options are..

• <timenav>: Set to true to enable time navigation. The default value is "false".
• <startdate>: The earliest date for the time navigation control. This value must be specified, in either of the formats above.
• <enddate>: The latest date for the time navigation control. This value must be specified, in either of the formats above.
• <timenavunit>: The number of steps between the start and end, on the navigation control. The default value is "200".
• <timenavpos>: The preset position of time navigation. This value must be between 0 and the value of <timenavunit>. The default value is "0".

Note!: worldKit will only handle timezone offsets, specified numerically. Any items without a timestamp are given a timestamp of the current time.

In experimental phase, worldKit can also "end events". Events that have concluded relative to the time slider control will be hidden. To set the end time of an event, we are currently supporting the RSS Event Module. As Calendar and Event formats are in flux, a different format may be preferred later on.

The elements are <ev:startdate> and <ev:enddate>. Declare the namespace with xmlns:ev="http://purl.org/rss/1.0/modules/event/". In contrast to the Module Specification, worldKit will support times in either of the formats listed above.