Externalize date picker string

app/assets/javascripts/vue_shared/components/pikaday.vue

 <script>
 import Pikaday from 'pikaday';
 import { parsePikadayDate, pikadayToString } from '~/lib/utils/datetime_utility';
+import { __ } from '~/locale';
 
 export default {
   name: 'DatePicker',
@@ -8,7 +9,7 @@ export default {
     label: {
       type: String,
       required: false,
-      default: 'Date picker',
+      default: __('Date picker'),
     },
     selectedDate: {
       type: Date,

app/assets/javascripts/vue_shared/components/sidebar/date_picker.vue

@@ -4,6 +4,7 @@ import datePicker from '../pikaday.vue';
 import toggleSidebar from './toggle_sidebar.vue';
 import collapsedCalendarIcon from './collapsed_calendar_icon.vue';
 import { dateInWords } from '../../../lib/utils/datetime_utility';
+import { __ } from '~/locale';
 
 export default {
   name: 'SidebarDatePicker',
@@ -42,7 +43,7 @@ export default {
     label: {
       type: String,
       required: false,
-      default: 'Date picker',
+      default: __('Date picker'),
     },
     selectedDate: {
       type: Date,

locale/gitlab.pot

@@ -2501,6 +2501,9 @@ msgstr ""
 msgid "Data is still calculating..."
 msgstr ""
 
+msgid "Date picker"
+msgstr ""
+
 msgid "Debug"
 msgstr ""