[gnome-calendar] week-header: fix calc of events' start and end positions

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 669869cf3f7c81313527f740669abdc71c0cece6
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Mar 15 17:45:49 2017 +0530

    week-header: fix calc of events' start and end positions
    
    Another shot in this issue. Again.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780051

 src/views/gcal-week-header.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/views/gcal-week-header.c b/src/views/gcal-week-header.c
index f44f7d0..5707f75 100644
--- a/src/views/gcal-week-header.c
+++ b/src/views/gcal-week-header.c
@@ -1630,13 +1630,13 @@ gcal_week_header_add_event (GcalWeekHeader *self,
 
   /* Start position */
   if (datetime_compare_date (start_date, week_start) >= 0)
-    start = g_date_time_get_day_of_week (start_date) % 7;
+    start = floor (g_date_time_difference (start_date, week_start) / G_TIME_SPAN_DAY);
   else
     start = 0;
 
   /* End position */
   if (g_date_time_compare (end_date, week_end) <= 0)
-    end = (g_date_time_get_day_of_week (end_date) - all_day) % 7;
+    end = floor (g_date_time_difference (end_date, week_start) / G_TIME_SPAN_DAY) - all_day;
   else
     end = 6;