# Welcome to the Highcharts Gantt JS (gantt) Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# lang.locale

The browser locale to use for date and number formatting. The actual locale used for each chart is determined in three steps:

1. If this `lang.locale` option is specified, it is used.
2. Else, look for the closest ancestor HTML element with a `lang` attribute, typically the `<html>` element.
3. If no 'lang' attribute is found, use the default browser locale.

Use `en-GB`, British English, for approximate consistency with Highcharts v < 12.