Removed buttons instead clicking date sets it

app/assets/javascripts/due_date_select.js.coffee

 class @DueDateSelect
   constructor: ->
-    $loading = $('.js-issuable-update .due_date').find('.block-loading').hide()
+    $loading = $('.js-issuable-update .due_date')
+      .find('.block-loading')
+      .hide()
 
     $('.js-due-date-select').each (i, dropdown) ->
       $dropdown = $(dropdown)
       $dropdownParent = $dropdown.closest('.dropdown')
-      $addBtn = $('.js-due-date-add', $dropdownParent)
       $datePicker = $dropdownParent.find('.js-due-date-calendar')
       $block = $dropdown.closest('.block')
       $selectbox = $dropdown.closest('.selectbox')
@@ -22,13 +23,10 @@ class @DueDateSelect
           $value.removeAttr('style')
       )
 
-      $addBtn.on 'click', (e) ->
-        e.preventDefault()
-        e.stopPropagation()
-
+      addDueDate = ->
         # Create the post date
         value = $("input[name='#{fieldName}']").val()
-        mediumDate = $.datepicker.formatDate("M d, yy", new Date(value))
+        mediumDate = $.datepicker.formatDate('M d, yy', new Date(value))
 
         data = {}
         data[abilityName] = {}
@@ -48,13 +46,15 @@ class @DueDateSelect
             $sidebarValue.html(mediumDate)
         ).done (data) ->
           $dropdown.trigger('loaded.gl.dropdown')
-          $dropdown.trigger('hidden.gl.dropdown')
+          $dropdown.dropdown('toggle')
           $loading.fadeOut()
 
       $datePicker.datepicker(
-        dateFormat: "yy-mm-dd",
+        dateFormat: 'yy-mm-dd',
         defaultDate: $("input[name='#{fieldName}']").val()
         altField: "input[name='#{fieldName}']"
+        onSelect: ->
+          addDueDate()
       )
 
     $(document)

app/assets/javascripts/issuable_context.js.coffee

@@ -33,7 +33,6 @@ class @IssuableContext
             $block.find('.dropdown-menu-toggle').trigger 'click'
           , 0
 
-
     $(".right-sidebar").niceScroll()
 
   initParticipants: ->

app/views/shared/issuable/_sidebar.html.haml

@@ -100,16 +100,11 @@
                 %button.dropdown-menu-toggle.js-due-date-select{ type: "button", data: { toggle: "dropdown", field_name: "#{issuable.to_ability_name}[due_date]", ability_name: issuable.to_ability_name, issue_update: issuable_json_path(issuable) } }
                   %span.dropdown-toggle-text
                     Due date
-                  = icon('chevron-down')
+                  = icon("chevron-down")
                 .dropdown-menu.dropdown-menu-due-date
                   = dropdown_title("Due date")
                   = dropdown_content do
                     .js-due-date-calendar
-                  .dropdown-footer.dropdown-due-date-footer.clearfix
-                    %button.btn.btn-primary.pull-left.js-due-date-add{ type: "button" }
-                      Add
-                    %button.btn.btn-default.pull-right{ type: "button" }
-                      Cancel
 
       - if issuable.project.labels.any?
         .block.labels