diff --git a/event/static/js/calendar.js b/event/static/js/calendar.js
index 9256c3b..4002700 100644
--- a/event/static/js/calendar.js
+++ b/event/static/js/calendar.js
@@ -53,6 +53,7 @@ class Calendar {
     this.createEventContainer();
     this.createEventDetailsContainer();
 
+    this.updateTimeSlotContainerGridStyle();
     this.updateEventContainerGridStyle();
 
     this.createTimeSlots();
@@ -153,9 +154,16 @@ class Calendar {
     }
   }
 
+  updateTimeSlotContainerGridStyle () {
+    this.timeSlotsContainerNode.css("grid-template-columns",
+                                    `repeat(${this.nbHoursToDisplay}, ${100 / this.nbHoursToDisplay }%)`);
+  }
+
   updateTimeSlots () {
     this.timeSlotsContainerNode.empty();
+
     this.createTimeSlots();
+    this.updateTimeSlotContainerGridStyle();
   }
 
   getHourSlotWidth () {