Humanize dates in timeline

app/locales/taiga/locale-en.json

@@ -1225,6 +1225,7 @@
         "CLIENT_REQUIREMENT": "Client Requirement",
         "BLOCKED": "Blocked",
         "VALUES": {
+            "NOT_SET": "not set",
             "UNASSIGNED": "unassigned"
         },
         "FIELDS": {
@@ -1234,6 +1235,7 @@
             "TYPE": "type",
             "ASSIGNED_TO": "assigned to",
             "ASSIGNED_USERS": "assigned users",
+            "DUE_DATE": "due date",
             "MILESTONE": "sprint",
             "COLOR": "color"
         }

app/modules/components/due-date/due-date-button.jade

@@ -1,5 +1,4 @@
-a.due-date-button.button-gray.is-editable(
-    href=""
+label.due-date-button.button-gray.is-editable(
     ng-if="vm.visible()"
     ng-disabled="vm.disabled()"
     ng-class="vm.color()"

app/modules/history/history/history-diff.jade

@@ -38,6 +38,11 @@
 )
     include history-templates/history-assigned-users
 
+.diff-wrapper(
+    ng-if="vm.type == 'due_date'"
+)
+    include history-templates/history-due-date
+
 .diff-wrapper(
     ng-if="vm.type == 'tags'"
 )

app/modules/history/history/history-templates/history-due-date.jade

@@ -0,0 +1,13 @@
+.diff-status-wrapper
+    span.key(
+        translate="ACTIVITY.FIELDS.DUE_DATE"
+    )
+    span.diff(ng-if="vm.diff[0]") {{vm.diff[0] | momentFormat:'DD MMM YYYY'}}
+    span.diff(ng-if="!vm.diff[0]" translate="ACTIVITY.VALUES.NOT_SET")
+
+    tg-svg(
+        svg-icon="icon-arrow-right"
+    )
+
+    span.diff(ng-if="vm.diff[1]") {{vm.diff[1] | momentFormat:'DD MMM YYYY'}}
+    span.diff(ng-if="!vm.diff[1]" translate="ACTIVITY.VALUES.NOT_SET")

app/modules/user-timeline/user-timeline-item/user-timeline-item-title.service.coffee

@@ -72,6 +72,14 @@ class UserTimelineItemTitle
                 if value == null && timeline.getIn(["data", "value_diff", "key"]) == 'assigned_to'
                     value = @translate.instant('ACTIVITY.VALUES.UNASSIGNED')
 
+                # due date
+                else if timeline.getIn(["data", "value_diff", "key"]) == 'due_date'
+                    if value
+                        prettyDate = @translate.instant("COMMON.PICKERDATE.FORMAT")
+                        value = moment(value, "YYYY-MM-DD").format(prettyDate)
+                    else
+                        value = @translate.instant('ACTIVITY.VALUES.NOT_SET')
+
                 new_value = value
             else
                 new_value = timeline.getIn(["data", "value_diff", "value"]).first().get(1)