Template:Period span/brief/doc

Purpose
To provide a time span (from start to end) in millions of years for a geological period or pair of geological periods. The time span will automatically update when new information is available. The numerical part of the time span is linked to a graphical display.

Usage
There are two ways of using the template:

Examples:


 * produces "" (without the quotes), i.e. the time from the start of the Pragian to the end of the Pragian
 * produces "", i.e. the time from the start of the Silurian to the end of the Carboniferous.

The last optional parameter can be set to 1, 2, etc. to display that number of decimal places, or to -1, -2, etc. to round to the nearest 10, 100, etc. years. The default is 0, i.e. no decimal places are shown. If you do want to display decimal places then, except for very recent times, you should probably instead use the template Period span, which avoids an impression of spurious accuracy by including error bounds. Note that decimal places will not be shown if they are not present in the source data.

Examples:


 * produces ""
 * produces ""; because the start and end round to the same number, only one is shown
 * produces "".

Errors
If this template generates an error, it is likely to be because the period is missing from next period or period start. Please go ahead and add it in the appropriate place (once you've checked your spelling!).

You also need to add the period to period start error so that other templates which display geological dates, such as period span, which shows more details, will work properly.

Period templates
This list is incomplete. You may help by expanding it


 * Template:Next period
 * Template:Period color
 * Template:Period end
 * Template:Period end error
 * Template:Period infoboxes
 * Template:Period span
 * Template:Period span/brief
 * Template:Period start
 * Template:Period start error