Conflict between timezones in "Insert date / time"


When I use the use “insert date / time” icon to insert a date and then it seems that there’s a conflict between the time in Oslo (GMT+1) and the ETC/GMT+1. Is this a bug or there’s actually a difference between GMT+1 & ETC/GMT+1?

Here’s a live example: Monday, November 8, 2021 7:00 PM

I thought the time is supposed to be the same?


I’m afraid the technical reason here is pretty confusing - you can read about it at Moment Timezone | Docs

POSIX compatibility requires that the offsets are inverted. Therefore, Etc/GMT-X will have an offset of +X and Etc/GMT+X will have an offset of -X . This is a result of IANA’s Time Zone Database and not an arbitrary choice by Moment.js. Thus, using locality based identifiers is preferred over fixed-offset identifiers.

So, in IANA’s Time Zone database, Europe/Oslo is currently equivalent to Etc/GMT-1

Monday, November 8, 2021 7:00 PM

I do wonder if we could/should introduce our own UTC+1, UTC+2, timezone aliases (without the Etc/ prefix). :thinking: (cc @joffreyjaffeux)


If it’s straightforward, I would probably suggest the removal of the Etc timezones as well. With the exception of some POSIX / time related Discourse instances, these timezones will be largely irrelevant and often confusing if a user wants to target an offset rather than a locale. They would appear before GMT/UTC in the list and the average user won’t know what the Etc prefix means.

If not removed, the prefix should be included in the display of the inserted time. Perhaps even with some indication that it might not be what the user expects, e.g. Etc/GMT+1 (= GMT-1)


@david thank you for the response and reference! So from what I concluded as a the solution for now, it would be to avoid using ETC/GMT and instead use the name of the city.