Error when setting timezone to GMT Offset in the new personal settings

Summary

Error when setting timezone to GMT Offset in the new personal settings

Steps to Reproduce

1. Go to your personal settings
2. Edit your timezone to GMT Offset
3. Choose any offset and try to save
4. ERROR: Couldn't save your preferences, something went wrong. Try again.

Expected Results

The timezone is saved

Actual Results

Cannot saveb the timezone when choosing GMT Offset

Notes

Workaround

Use cURL to update the timezone. You can also use the browser console to do this.

1. Browse to https://<domain_name>.atlassian.net/secure/ViewPersonalSettings.jspa.
2. Activate the browser developer console and navigate to the 'network' tab.
3. Attempt a change to the GMT Offset timezone. You will receive an error message and the error will be reflected in the network tab.
4. Locate the end point that is returning 400 error : https://<domain_name>.atlassian.net/rest/internal/2/user/preferences
5. Copy as fetch as shown in the screenshot below :
   
6. Paste it on the developer console. You will see something like this :

   fetch("https://<domain_name>.atlassian.net/rest/internal/2/user/preferences", {"credentials":"include","headers":{"accept":"application/json,text/javascript,*/*","accept-language":"en-US,en;q=0.9","content-type":"application/json"},"referrer":"https://<domain_name>.atlassian.net/secure/ViewPersonalSettings.jspa","referrerPolicy":"no-referrer-when-downgrade","body":"{\"timezone\":\"GMT Offset/GMT+12\",\"locale\":\"en_US\",\"notify\":false,\"userNotificationsMimeType\":\"html\"}","method":"POST","mode":"cors"});
   

   Modify the following :

   "body":"{\"timezone\":\"GMT Offset/GMT+12\",\"locale\":\"\",\"notify\":true,\"userNotificationsMimeType\":\"html\"}"
   

   To :

   "body":"{\"timezone\":\"Etc/GMT+12\",\"locale\":\"\",\"notify\":true,\"userNotificationsMimeType\":\"html\"}"
   

   The main idea is to change the 'GMT Offset' to 'Etc'. Do make sure that the method is set to POST as well.

7. Enter to execute the fetch request. The change will be administered.