The
resolvedOptions
function on Intl.DateTimeFormat.prototype provides a number of pieces of
information about the client computer. It includes information such as the
locale and the numbering system. It also has the time zone for that machine.
Try running this line of JavaScript in your own browser.
$ Intl.DateTimeFormat().resolvedOptions().timeZoneWhen I run it, I get America/Chicago.
You can use this within your client-side code as a way of determining in which time zone your users are.