diff --git a/cara/apps/calculator/static/js/form.js b/cara/apps/calculator/static/js/form.js
index b48bc8cd..72d80711 100644
--- a/cara/apps/calculator/static/js/form.js
+++ b/cara/apps/calculator/static/js/form.js
@@ -431,13 +431,11 @@ function validateLunchBreak(obj) {
   }
 
   //Check if exposed/infected lunch times within exposed/infected presence times
-  var startID = groupID.split("_")[1] + "_start";
-  var finishID = groupID.split("_")[1] + "_finish";
-  
-  var globalStart = parseValToNumber(document.getElementById(startID).value);
-  var globalFinish = parseValToNumber(document.getElementById(finishID).value);
+  var activityID = $(obj).data('lunch-for');
+  var activityStart = parseValToNumber($(".start_time[data-time-group='"+activityID+"']")[0].value);
+  var activityFinish = parseValToNumber($(".finish_time[data-time-group='"+activityID+"']")[0].value);
 
-  if ((time < globalStart) || (time > globalFinish)) {
+  if ((time < activityStart) || (time > activityFinish)) {
     $(obj).addClass("red_border lunch_break_error");
     if (!$(otherObj).hasClass("red_border") && !$(finishObj).hasClass("finish_time_error")) {
       insertSpanAfter(finishObj, "Lunch break must be within activity times");
@@ -495,8 +493,15 @@ $(document).ready(function () {
   $(".start_time").change(function() {validateFinishTime(this)});
 
   //Validate lunch times
-  $("input[required].lunch").each(function() {validateLunchBreak(this)});
-  $("input[required].lunch").change(function() {validateLunchBreak(this)});
+  $("[data-lunch-for]").each(function() {validateLunchBreak(this)});
+  $("[data-lunch-for]").change(function() {validateLunchBreak(this)});
+  $("[data-lunch-break]").change(function() {
+    var lunchGroup = $(this).data('lunch-break');
+    var lunchStart = $(".start_time[data-time-group='"+lunchGroup+"']")[0];
+    var lunchFinish = $(".finish_time[data-time-group='"+lunchGroup+"']")[0];
+    validateLunchBreak(lunchStart)
+    validateLunchBreak(lunchFinish)
+  });
 
   var radioValue = $("input[name='event_type']:checked");
   if (radioValue.val()) {
diff --git a/cara/apps/calculator/templates/calculator.form.html.j2 b/cara/apps/calculator/templates/calculator.form.html.j2
index 5db0526d..4691274f 100644
--- a/cara/apps/calculator/templates/calculator.form.html.j2
+++ b/cara/apps/calculator/templates/calculator.form.html.j2
@@ -134,8 +134,8 @@
                     <option value="training">Training</option>
                     <option value="gym">Gym</option>
                   </select><br>
-    Start: <input type="time" id="activity_start" class="start_time" data-time-group="activity" name="activity_start" value="09:00" required> &nbsp;&nbsp;
-    Finish: <input type="time" id="activity_finish" class="finish_time" data-time-group="activity" name="activity_finish" value="18:00" required><br>
+    Start: <input type="time" id="activity_start" class="start_time" data-time-group="activity" data-lunch-break="lunch_activity" name="activity_start" value="09:00" required> &nbsp;&nbsp;
+    Finish: <input type="time" id="activity_finish" class="finish_time" data-time-group="activity" data-lunch-break="lunch_activity" name="activity_finish" value="18:00" required><br>
     Infected person(s) presence: <br>
     Start: <input type="time" id="infected_start" class="start_time" data-time-group="infected" name="infected_start" value="09:00"required> &nbsp;&nbsp;
     Finish: <input type="time" id="infected_finish" class="finish_time" data-time-group="infected" name="infected_finish" value="18:00"  required><br>
@@ -178,8 +178,8 @@
       <label for="lunch_option_yes">Yes</label><br>
     
     <div id="DIVlunch_break">
-        Start: <input type="time" id="lunch_start" class="start_time lunch" data-time-group="lunch_activity" name="lunch_start" value="12:30" required> &nbsp;&nbsp;
-        Finish: <input type="time" id="lunch_finish" class="finish_time lunch" data-time-group="lunch_activity" name="lunch_finish" value="13:30" required><br>
+        Start: <input type="time" id="lunch_start" class="start_time" data-time-group="lunch_activity" data-lunch-for="activity" name="lunch_start" value="12:30" required> &nbsp;&nbsp;
+        Finish: <input type="time" id="lunch_finish" class="finish_time" data-time-group="lunch_activity" data-lunch-for="activity" name="lunch_finish" value="13:30" required><br>
     </div>
 
     <!-- Coffee Options -->