How to parse timezone with date

Question

How do we get the date utility to parse the timezone strings?

$>date -d "2018-02-21T02:22:33.221" "+%Y-%m-%dT%H:%M:%S.%3N %Z"
2018-02-20T14:22:33.221 EST

But

$>date -d "2018-02-21T02:22:33.221 EST" "+%Y-%m-%dT%H:%M:%S.%3N %Z"
date: invalid date `2018-02-21T02:22:33.221 EST'

This the local info:

$>uname -r
2.6.32-696.13.2.el6.x86_64

$>date
Tue Jan 16 09:58:52 EST 2018

$>date --version
date (GNU coreutils) 8.4
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by David MacKenzie.

Answer 1

ISO8601 allows you to replace T with space. Just do it, and your command will work fine:

# date -d "2018-02-21T02:22:33.221 EST" "+%Y-%m-%dT%H:%M:%S.%3N %Z"
date: invalid date `2018-02-21T02:22:33.221 EST'

but:

# date -d "2018-02-21 02:22:33.221 EST" "+%Y-%m-%d %H:%M:%S.%3N %Z"
2018-02-21 10:22:33.221 MSK