ISO-8601 With offset displaying local time

[marnusw]

ISO-8601 With offset displaying local time

[marnusw]

It's an interesting one. These are the steps currently required:

1. toDate parses the string taking the offset into account and giving the correct timestamp, i.e. the UTC time you're looking for.
2. Use utcToZoneTime(dateWithTz, timeZone) to effectively indicate for which time zone you want to format.
3. format(dateWithTz, ' hh:mm a - eeee, MMMM d, yyyy') to display for that time zone.

Whenever I've used this / thought about it the time zone to display for was available as an IANA time zone string. In your case it's not, because it's contained in the original date string.

I think utcToZoneTime might work with offsets as well as IANA time zones, so you could try slicing it off the date in order to call this (can't quite remember and didn't check the code now). Granted it's a bit messy though.

I won't have time to think about this right now, but if you can figure it out and if necessary propose a PR I'll find time to consider it.

[bringking]

@marnusw so using the offset worked as intended, but I had to extract it from the ISO String like so

import { toDate, format, utcToZonedTime } from 'date-fns-tz';

const isoDateString = '2020-01-09T20:00-05:00';
const dateWithTz = toDate(isoDateString);
const [offset] = isoDateString.match(/(-|\+)([0-9][0-9]):([0-9][0-9])$/);
const timeZonedDate = utcToZonedTime(dateWithTz, offset);
format(timeZonedStartDate, 'eeee, MMMM d, yyyy', { timeZone: offset })

I will close this since it's technically possible, but have to jump through hoops. If there is a better way, would be interested to know it.