The IANA timezone database is the official nomenclature for timezone information, and is what you should use, whenever possible.

Humans though, are goofballs, and use a whole different informal scheme.

• In (North) America, we use: PST, MST, EST...
• in Europe (lately) they use: WEST, CEST, EEST...
• in Africa they use: EAT, CAT, WAST...
• in Australia they use: AWST, AEDT, ACST...

these line-up with the IANA timezones sometimes. Other times they don't.

These names collide all the time, (like IST - irish/indian stardard time).

These names produce all-sorts of ambiguities, regarding DST-changes - Both Winnipeg and Mexico City are CST, but have a much different DST schedule:

(thanks timeanddate.com!)

Of course, there's a bunch of political/historical/disputed stuff going on, too. Apologies if I step into this unknowingly.

This library is an attempt to 'soften' this exchange, between human-IANA, using some opinionated-but-common-sense rules and decision-making.

It was built for use in the spacetime timezone library, but may be used without it.

const informal = require('spacetime-informal')

informal.find('EST')
// 'America/New_York'

informal.find('central')
// 'America/Chicago'

informal.find('venezuela')
// 'America/Caracas'

informal.find('south east asia')
// 'Asia/Bangkok'

informal.display('Toronto')
/*{
  standard: { name: 'Eastern Standard Time', abbrev: 'EST' },
  daylight: { name: 'Eastern Daylight Time', abbrev: 'EDT' },
  iana: 'Canada/Toronto'
}*/

it was built to be as forgiving as possible, and return the most common-sense IANA timezone id from user-input.

along with spacetime, you can generate human-friendly time formats, like this:

const spacetime = require('spacetime')
const informal = require('spacetime-informal')

let display = informal.display('montreal')
let s = spacetime.now(display.iana)
let abbrev = s.isDST() ? display.daylight.abbrev : display.standard.abbrev // (add some null-checks)
let time = `${s.time()} ${abbrev}`
// '4:20pm EDT'

work-in-progress.

MIT