Django timezone tag raising error when Etc/GMT-3 used in template

i am using this template tags on my project

{% load tz %}
{% get_current_timezone as TIME_ZONE %}
{% timezone TIME_ZONE %}
{% endtimezone %}

it is raising this error when TIME_ZONE suplied with Etc/GMT-3 value.

  File "/usr/local/lib/python3.10/site-packages/django/utils/", line 133, in activate
    _active.value = zoneinfo.ZoneInfo(timezone)
  File "/usr/local/lib/python3.10/zoneinfo/", line 24, in load_tzdata
    raise ZoneInfoNotFoundError(f"No time zone found with key {key}")
zoneinfo._common.ZoneInfoNotFoundError: 'No time zone found with key +03'

i see in my current django library it use the following function when timezone tag is called.
this is in env/lib/python3.9/site-packages/django/utils/

def _get_timezone_name(timezone):
    Return the offset for fixed offset timezones, or the name of timezone if
    not set.
    return timezone.tzname(None) or str(timezone)

the function return +03 when supplied with Etc/GMT-3 timezone, then it giving me above error. is it a bug?

anyway, i need to create my own tag because of it.