The timeline syntax is available on Mediawiki.

For an example of the <timeline></timeline> syntax in use, see Template:Timeline geological timescale.

The script commands define:

• Overall layout: ImageSize, PlotArea, Colors, BackgroundColors, AlignBars
• Interpretation and presentation of dates and periods: DateFormat, Period, ScaleMajor, ScaleMinor, TimeAxis
• Events, periods and descriptive texts: PlotData, TextData
• How to order, divide, and name groups of events and periods: BarData, Legend, LineData
• Shorthands for pieces of script code that occur multiple times: Define

The following commands are mandatory: ImageSize, PlotArea, Period and TimeAxis. At least one of the following commands is required: PlotData and/or TextData. Either or both can occur multiple times. All other commands are optional.

• Wikipedia:Timeline standards
• Wikipedia:EasyTimeline
• mw:Extension:EasyTimeline