Description of problem:

gnome-calendar doesn't utilize LC_TIME to determine first week of day. It seems that LC_MESSAGES value is used instead.

I use Czech for all locales except for LC_MESSAGES, which I have set to English.

Gnome Calendar menu bars, buttons, etc. is shown in English (correctly), the month names are shown in Czech (correctly), but the first day of week is Sunday (incorrectly as it is Monday in Czech locale).

It's worth to say that the calendar in gnome shell notification area correctly shows Monday as a first day of week.

% localectl 
   System Locale: LANG=cs_CZ.utf8
                  LC_MESSAGES=en_US.utf8
       VC Keymap: cz-lat2
      X11 Layout: cz
     X11 Variant: qwerty

% env | grep -e LC -e LANG                                                           
LC_MESSAGES=en_US.utf8
LANG=cs_CZ.utf8
GDM_LANG=cs_CZ.UTF-8

% xargs -0 printf "%s\n" < /proc/$(pidof gnome-calendar)/environ | grep -e LANG -e LC
LC_MESSAGES=en_US.utf8
GDM_LANG=cs_CZ.UTF-8
LANG=cs_CZ.UTF-8


Version-Release number of selected component (if applicable):
gnome-calendar-3.16.2-1.fc22.x86_64

How reproducible:
always

Steps to Reproduce:
1. set locales according to my configuration
2. start gnome-calendar (from gnome or console)
3.

Actual results:
Sunday is shown as a first day of week.

Expected results:
Monday is shown as a first day of week.

Additional info:
Running 'LC_MESSAGES= gnome-calendar' make things work.