I don't think so. For example here on Windows XP, emacs -Q with current
trunk, evaluating
(progn
(custom-set-faces
'(mode-line ((t (:background "#000040" :foreground "wheat" :box (:line-width 2 :color
"#000040") :weight bold :family "Verdana"))))
'(mode-line-inactive ((t (:inherit mode-line :background "grey48" :foreground "wheat"
:box (:line-width 2 :color "#000040"))))))
(setq calendar-week-start-day 1)
(calendar))
gives screenshot calendar-1.png while evaluating
(progn
(custom-set-faces
'(mode-line ((t (:background "#000040" :foreground "wheat" :box (:line-width 2 :color
"#000040") :weight bold :family "Verdana"))))
'(mode-line-inactive ((t (:inherit mode-line :background "grey48" :foreground "wheat"
:box (:line-width 2 :color "#000040"))))))
(setq calendar-week-start-day 1)
(sit-for 0)
(calendar))
gives the expected screenshot calendar-2.png.