diff --git a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/getters.js b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/getters.js
index a33d49dbb..8cf1cc8bc 100644
--- a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/getters.js
+++ b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/getters.js
@@ -2,15 +2,33 @@ import {USER_CALENDAR_SHOW_RANGES, USER_CALENDAR_SHOW_EVENTS} from './../const';
 import {calendarRangeToFullCalendarEvent} from './utils';
 
 export default {
+  /**
+   * get the main user of the event/Calendar
+   *
+   * @param state
+   * @returns {*|null}
+   */
   getMainUser(state) {
     return state.activity.mainUser || null;
   },
+  /**
+   * return the date of the event/Calendar
+   *
+   * @param state
+   * @returns {Date}
+   */
   getEventDate(state) {
     if (null === state.activity.start) {
       return new Date();
     }
     throw 'transform date to object ?';
   },
+  /**
+   * Compute the event sources to show on the FullCalendar
+   *
+   * @param state
+   * @returns {*[]}
+   */
   getEventSources(state) {
     console.log('getEventSources');
     let sources = [];
@@ -50,12 +68,32 @@ export default {
 
     return sources;
   },
+  /**
+   * get the user data for a specific user
+   *
+   * @param state
+   * @returns {function(*): unknown}
+   */
   getUserData: (state) => (user) => {
     return state.usersData.get(user.id);
   },
+  /**
+   * return true if the user has an entry in userData
+   *
+   * @param state
+   * @returns {function(*): boolean}
+   */
   hasUserData: (state) => (user) => {
     return state.usersData.has(user.id);
   },
+  /**
+   * return true if there was a fetch query for event between this date (start and end),
+   * those date are included.
+   *
+   * @param state
+   * @param getters
+   * @returns {(function({user: *, start: *, end: *}): (boolean))|*}
+   */
   isCalendarRangeLoadedForUser: (state, getters) => ({user, start, end}) => {
     if (!getters.hasUserData(user)) {
       return false;
@@ -69,6 +107,9 @@ export default {
 
     return false;
   },
+
+
+
   suggestedEntities(state, getters) {
     if (typeof (state.activity.accompanyingPeriod) === 'undefined') {
       return [];
diff --git a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/index.js b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/index.js
index 5eecb9471..12f9240f8 100644
--- a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/index.js
+++ b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/index.js
@@ -22,13 +22,25 @@ const store = createStore({
      activity: mapEntity(window.entity), // activity is the calendar entity actually
      currentEvent: null,
      availableLocations: [],
+     /**
+      * the current user
+      */
      me: null,
-     initialDate: null,
+     /**
+      * store information about current view
+      */
      currentView: {
        start: null,
        end: null,
        users: new Map(),
      },
+     /**
+      * store a list of existing event, to avoid storing them twice
+      */
+     existingEvents: new Set(),
+     /**
+      * store user data
+      */
      usersData: new Map(),
    },
     getters,
diff --git a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/mutations.js b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/mutations.js
index 2aa1f3ab6..e516f2fa9 100644
--- a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/mutations.js
+++ b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store/mutations.js
@@ -44,6 +44,15 @@ export default {
     }
     ;
   },
+  /**
+   * Add CalendarRange object for an user
+   *
+   * @param state
+   * @param user
+   * @param ranges
+   * @param start
+   * @param end
+   */
   addCalendarRangesForUser(state, {user, ranges, start, end}) {
     let userData;
     if (state.usersData.has(user.id)) {
@@ -53,7 +62,14 @@ export default {
       state.usersData.set(user.id, userData);
     }
 
-    const eventRanges = ranges.map(r => calendarRangeToFullCalendarEvent(r));
+    const eventRanges = ranges
+      .filter(r => !state.existingEvents.has(`range_${r.id}`))
+      .map(r => {
+        // add to existing ids
+        state.existingEvents.add(`range_${r.id}`);
+        return r;
+      })
+      .map(r => calendarRangeToFullCalendarEvent(r));
 
     userData.calendarRanges = userData.calendarRanges.concat(eventRanges);
     userData.calendarRangesLoaded.push({start, end});