diff --git a/app/pages/resource/reservation-calendar/ReservationCalendarContainer.js b/app/pages/resource/reservation-calendar/ReservationCalendarContainer.js
index 7892a40ec..2f8f37586 100644
--- a/app/pages/resource/reservation-calendar/ReservationCalendarContainer.js
+++ b/app/pages/resource/reservation-calendar/ReservationCalendarContainer.js
@@ -11,6 +11,7 @@ import moment from 'moment';
 import first from 'lodash/first';
 import last from 'lodash/last';
 import orderBy from 'lodash/orderBy';
+import debounce from 'lodash/debounce';
 
 import { addNotification } from 'actions/notificationsActions';
 import {
@@ -150,12 +151,12 @@ export class UnconnectedReservationCalendarContainer extends Component {
     const isOpen = Boolean(timeSlots.length);
     const showTimeSlots = isOpen && !reservingIsRestricted(resource, date);
     const selectedDateSlots = this.getSelectedDateSlots(timeSlots, selected);
-
     return (
       <div className="reservation-calendar">
         {showTimeSlots && (
           <TimeSlots
-            addNotification={actions.addNotification}
+            addNotification={debounce(actions.addNotification, 100)}
+            // TODO: Im a h@ck, remove me
             isAdmin={isAdmin}
             isEditing={isEditing}
             isFetching={isFetchingResource}
diff --git a/app/pages/resource/reservation-calendar/time-slots/TimeSlot.js b/app/pages/resource/reservation-calendar/time-slots/TimeSlot.js
index 230996ca5..853bae3c4 100644
--- a/app/pages/resource/reservation-calendar/time-slots/TimeSlot.js
+++ b/app/pages/resource/reservation-calendar/time-slots/TimeSlot.js
@@ -10,11 +10,13 @@ import { padLeft } from 'utils/timeUtils';
 class TimeSlot extends PureComponent {
   static propTypes = {
     addNotification: PropTypes.func.isRequired,
+    // eslint-disable-next-line react/no-unused-prop-types
     isDisabled: PropTypes.bool,
     isAdmin: PropTypes.bool.isRequired,
     showClear: PropTypes.bool.isRequired,
     isHighlighted: PropTypes.bool.isRequired,
     isLoggedIn: PropTypes.bool.isRequired,
+    // eslint-disable-next-line react/no-unused-prop-types
     isSelectable: PropTypes.bool.isRequired,
     isUnderMinPeriod: PropTypes.bool.isRequired,
     onClear: PropTypes.func.isRequired,
@@ -32,9 +34,34 @@ class TimeSlot extends PureComponent {
     isDisabled: false,
   }
 
+  static getDerivedStateFromProps(prop) {
+    const {
+      slot, resource, isDisabled, isSelectable, selected, isLoggedIn
+    } = prop;
+    const isPast = new Date(slot.end) < new Date();
+    const isReservable = (resource.reservableAfter
+      && moment(slot.start).isBefore(resource.reservableAfter));
+    const disabled = isDisabled
+      || !isLoggedIn
+      || (!isSelectable && !selected)
+      || !resource.userPermissions.canMakeReservations
+      || isReservable
+      || (!slot.editing && (slot.reserved || isPast));
+
+    return {
+      disabled,
+      isPast
+    };
+  }
+
   constructor(props) {
     super(props);
     this.timeSlotRef = React.createRef();
+
+    this.state = {
+      disabled: false,
+      isPast: false,
+    };
   }
 
   componentDidMount() {
@@ -43,6 +70,15 @@ class TimeSlot extends PureComponent {
     }
   }
 
+  componentDidUpdate() {
+    const { selected } = this.props;
+
+    if (selected && selected === this.state.disabled) {
+      this.renderMinPeriodWarning();
+      this.props.onClear();
+    }
+  }
+
   getReservationInfoNotification(isLoggedIn, resource, slot, t) {
     if (new Date(slot.end) < new Date() || slot.reserved) {
       return null;
@@ -104,28 +140,18 @@ class TimeSlot extends PureComponent {
 
   render() {
     const {
-      isDisabled,
       isAdmin,
       showClear,
       isHighlighted,
-      isLoggedIn,
-      isSelectable,
       onClear,
       onMouseEnter,
       onMouseLeave,
-      resource,
       selected,
       slot,
     } = this.props;
-    const isPast = new Date(slot.end) < new Date();
-    const isReservable = (resource.reservableAfter
-      && moment(slot.start).isBefore(resource.reservableAfter));
-    const disabled = isDisabled
-      || !isLoggedIn
-      || (!isSelectable && !selected)
-      || !resource.userPermissions.canMakeReservations
-      || isReservable
-      || (!slot.editing && (slot.reserved || isPast));
+
+    const { disabled, isPast } = this.state;
+
     const reservation = slot.reservation;
     const isOwnReservation = reservation && reservation.isOwn;
     const start = new Date(slot.start);
diff --git a/app/pages/resource/reservation-calendar/time-slots/TimeSlots.js b/app/pages/resource/reservation-calendar/time-slots/TimeSlots.js
index c0a23cb3a..2d79a4e32 100644
--- a/app/pages/resource/reservation-calendar/time-slots/TimeSlots.js
+++ b/app/pages/resource/reservation-calendar/time-slots/TimeSlots.js
@@ -145,9 +145,8 @@ class TimeSlots extends Component {
         return null;
       }
       const slot = timeSlots[0];
-      const lastSlot = timeSlots[timeSlots.length - 2];
+      const lastSlot = timeSlots[timeSlots.length - 1];
       // last slot is selectable slot, which is slot before last slot in array
-
       const placeholderSize = timeSlotPlaceholderSizes[index];
 
       const slotDate = moment(slot.start).format(constants.DATE_FORMAT);
@@ -172,9 +171,7 @@ class TimeSlots extends Component {
           )}
 
           {timeSlots.map((timeSlot) => {
-            const isUnderMinPeriod = utils.isUnderMinPeriod(
-              selected, timeSlot, lastSlot, resource.minPeriod
-            );
+            const isUnderMinPeriod = utils.isUnderMinPeriod(timeSlot, lastSlot, resource.minPeriod);
 
             if (!lastSelectableFound && selected.length && timeSlot.reserved) {
               lastSelectableFound = utils.isSlotAfterSelected(timeSlot, selected);
diff --git a/app/pages/resource/reservation-calendar/utils.js b/app/pages/resource/reservation-calendar/utils.js
index 71a7b7695..6437a9819 100644
--- a/app/pages/resource/reservation-calendar/utils.js
+++ b/app/pages/resource/reservation-calendar/utils.js
@@ -120,22 +120,20 @@ function isHighlighted(slot, selected, hovered) {
  * by adding minPeriod to slot start time
  * and compare with last slot end time
  *
- * @param {Object} selected
  * @param {Object} slot
  * @param {Object} lastSlot
  * @param {String | undefined} minPeriod: minPeriod limit, usuall HH:MM:SS
  * @returns
  */
-function isUnderMinPeriod(selected, slot, lastSlot, minPeriod) {
-  if (!selected || !slot || !lastSlot) {
+function isUnderMinPeriod(slot, lastSlot, minPeriod) {
+  if (!slot || !lastSlot) {
     return false;
   }
 
   if (!slot.end || !lastSlot.end) {
     return false;
   }
-
-  if (!selected.length && minPeriod) {
+  if (minPeriod) {
     const minPeriodInMinutes = moment.duration(minPeriod).asMinutes();
     return moment(slot.start).add(minPeriodInMinutes, 'minutes') > (moment(lastSlot.end));
   }
diff --git a/app/pages/resource/reservation-calendar/utils.spec.js b/app/pages/resource/reservation-calendar/utils.spec.js
index c013c50cf..4518e6d2b 100644
--- a/app/pages/resource/reservation-calendar/utils.spec.js
+++ b/app/pages/resource/reservation-calendar/utils.spec.js
@@ -194,7 +194,7 @@ describe('pages/resource/reservation-calendar/utils', () => {
   });
 
   describe('isUnderMinPeriod', () => {
-    const minPeriod = '1:00:00';
+    const minPeriod = '2:00:00';
     const lastSlot = {
       start: '2015-10-10T15:00:00Z',
       end: '2015-10-10T15:30:00Z',
@@ -206,26 +206,24 @@ describe('pages/resource/reservation-calendar/utils', () => {
     };
 
     test('return false if required data is missing, wont throw error', () => {
-      const noLastSlot = utils.isUnderMinPeriod(selected, slot, undefined, minPeriod);
-      const noStartSlot = utils.isUnderMinPeriod(selected, undefined, lastSlot, minPeriod);
-      const noSelected = utils.isUnderMinPeriod(undefined, slot, lastSlot, minPeriod);
+      const noLastSlot = utils.isUnderMinPeriod(slot, undefined, minPeriod);
+      const noStartSlot = utils.isUnderMinPeriod(undefined, lastSlot, minPeriod);
 
       expect(noLastSlot).toBeFalsy();
       expect(noStartSlot).toBeFalsy();
-      expect(noSelected).toBeFalsy();
     });
     test('returns false if minPeriod is not defined', () => {
-      const actual = utils.isUnderMinPeriod(selected);
+      const actual = utils.isUnderMinPeriod(slot, lastSlot);
       expect(actual).toBe(false);
     });
 
     test('returns false if minPeriod is defined but start time slot already selected (allow time slot to be selected if start time is already selected)', () => {
-      const actual = utils.isUnderMinPeriod(selected, null, null, minPeriod);
+      const actual = utils.isUnderMinPeriod(null, null, minPeriod);
       expect(actual).toBe(false);
     });
 
     test('return false if its safe to select slot', () => {
-      const actual = utils.isUnderMinPeriod(selected, slot, lastSlot, minPeriod);
+      const actual = utils.isUnderMinPeriod(slot, lastSlot, minPeriod);
       expect(actual).toBe(false);
     });
 
@@ -234,22 +232,22 @@ describe('pages/resource/reservation-calendar/utils', () => {
         start: '2015-10-10T15:00:00Z',
       };
 
-      const actual = utils.isUnderMinPeriod(selected, slot, closeSlot, minPeriod);
+      const actual = utils.isUnderMinPeriod(slot, closeSlot, minPeriod);
       expect(actual).toBe(false);
     });
 
     test('return true if selected slot will not fulfill minPeriod', () => {
-      const actual = utils.isUnderMinPeriod(selected, inValidSlot, lastSlot, minPeriod);
-      expect(actual).toBe(false);
+      const actual = utils.isUnderMinPeriod(inValidSlot, lastSlot, minPeriod);
+      expect(actual).toBe(true);
     });
 
     test('return false if selected slot fulfill minPeriod', () => {
       const validSlot = {
-        start: '2015-10-10T14:00:00Z',
-        end: '2015-10-10T14:30:00Z',
+        start: '2015-10-10T13:30:00Z',
+        end: '2015-10-10T14:00:00Z',
       };
 
-      const actual = utils.isUnderMinPeriod(selected, validSlot, lastSlot, minPeriod);
+      const actual = utils.isUnderMinPeriod(validSlot, lastSlot, minPeriod);
       expect(actual).toBe(false);
     });
   });