வார்ப்புரு:Period span/brief/doc
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 {{See also cat|Geological period templates}}
 
 === 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:
 * &lt;code&gt;&lt;nowiki&gt;{{Period span/brief|period name|rounding (optional)}}&lt;/nowiki&gt;&lt;/code&gt;
 * &lt;code&gt;&lt;nowiki&gt;{{Period span/brief|first period name|second period name|rounding (optional)}}&lt;/nowiki&gt;&lt;/code&gt;.
 
 Examples:
 
 *  &lt;code&gt;&lt;nowiki&gt;{{period span/brief|Pragian}}&lt;/nowiki&gt;&lt;/code&gt; produces &quot;{{period span/brief|Pragian}}&quot; (without the quotes), i.e. the time from the start of the Pragian to the end of the Pragian
 *  &lt;code&gt;&lt;nowiki&gt;{{period span/brief|Silurian|Carboniferous}}&lt;/nowiki&gt;&lt;/code&gt; produces &quot;{{period span/brief|Silurian|Carboniferous}}&quot;, 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 {{tl|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:
 
 *  &lt;code&gt;&lt;nowiki&gt;{{period span/brief|Pragian|1}}&lt;/nowiki&gt;&lt;/code&gt; produces &quot;{{period span/brief|Pragian|1}}&quot;
 *  &lt;code&gt;&lt;nowiki&gt;{{period span/brief|Pragian|-1}}&lt;/nowiki&gt;&lt;/code&gt; produces &quot;{{period span/brief|Pragian|-1}}&quot;; because the start and end round to the same number, only one is shown
 *  &lt;code&gt;&lt;nowiki&gt;{{period span/brief|Silurian|Carboniferous|-1}}&lt;/nowiki&gt;&lt;/code&gt; produces &quot;{{period span/brief|Silurian|Carboniferous|-1}}&quot;.
 
 ===Errors===
 If this template generates an error, it is likely to be because the period is missing from {{tl|next period}} or {{tl|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 {{tl|period start error}} so that other templates which display geological dates, such as {{tl|period span}}, which shows more details, will work properly.
 
 ===Sources===
 For documentation on the sources of the dates and other information, see [[Template:Period start]].
 
 ==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]]
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 [[Category:Geological period templates|{{PAGENAME}}]]