month-cell: Use full-length month names when safe to do so

Full month names are easier to notice and read while scrolling,
and would be read more naturally by text-to-speech screen readers.

An exception must be made when today is near the beginning of the month,
as the weather forecast temperatures labels might also appear there.
In that case, use the abbreviated version of the month name label.

Fixes issue #962

src/gui/views/gcal-month-cell.c

@@ -182,12 +182,15 @@ update_weather (GcalMonthCell *self)
   GcalWeatherService *weather_service;
   GcalWeatherInfo *weather_info;
   GDate date;
+  gint day_of_month;
 
   if (!self->context)
     return;
 
+  day_of_month = g_date_time_get_day_of_month (self->date);
+
   g_date_set_dmy (&date,
-                  g_date_time_get_day_of_month (self->date),
+                  day_of_month,
                   g_date_time_get_month (self->date),
                   g_date_time_get_year (self->date));
 
@@ -211,11 +214,25 @@ update_weather (GcalMonthCell *self)
 
       gtk_image_set_from_icon_name (self->weather_icon, icon_name);
       gtk_label_set_text (self->temp_label, temp_str);
+
+      /* Use a short month name label to avoid conflicting with the weather forecast's labels */
+      if (day_of_month == 1)
+        {
+          g_autofree gchar *month_name = g_date_time_format (self->date, "%b");
+          gtk_label_set_text (self->month_name_label, month_name);
+        }
     }
   else
     {
       gtk_image_clear (self->weather_icon);
       gtk_label_set_text (self->temp_label, "");
+
+      /* No risk of conflicting with the weather forecast labels in their absence, use the full month name label */
+      if (day_of_month == 1)
+        {
+          g_autofree gchar *month_name = g_date_time_format (self->date, "%B");
+          gtk_label_set_text (self->month_name_label, month_name);
+        }
     }
 }
 
@@ -486,7 +503,7 @@ gcal_month_cell_set_date (GcalMonthCell *self,
   gtk_widget_set_visible (GTK_WIDGET (self->month_name_label), day_of_month == 1);
   if (day_of_month == 1)
     {
-      g_autofree gchar *month_name = g_date_time_format (date, "%b");
+      g_autofree gchar *month_name = g_date_time_format (date, "%B");
       gtk_label_set_text (self->month_name_label, month_name);
       gtk_widget_add_css_class (GTK_WIDGET (self->month_name_label), "heading");
       gtk_widget_add_css_class (GTK_WIDGET (self->day_label), "heading");