What am I doing wrong here?

[pjb3]

Say I have a string with a US/Eastern offset in it. I can parse it into a utcDate like this:

> const { format, zonedTimeToUtc } = require("date-fns-tz")
undefined
> const utcDate = zonedTimeToUtc('2020-09-21T11:50:00-04:00')
undefined
> utcDate
2020-09-21T15:50:00.000Z

Now if I try to use format to print it back out in US Eastern, I get this:

> format(utcDate, 'yyyy-MM-dd HH:mm z OOOO', { timeZone: 'US/Eastern' })
'2020-09-21 08:50 EDT GMT-04:00'

Why isn't that 2020-09-21 11:50 EDT? This is in a node.js console and my time zone is US/Pacific.

[michaelyuen]

I think your format string is incorrect. O (letter) is for Timezone (GMT): https://date-fns.org/v2.16.1/docs/format

Just removing that portion, the z should do what you want: 'yyyy-MM-dd HH:mm z'

I'd also recommend using America/New_York as US/Eastern is deprecated: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

Reproduction: https://codesandbox.io/s/date-fns-tz-question-4n9u4