Remove help text from golive / expiry date fields

The only purpose it served was to tell you the date format - which is redundant since the date picker does that for you, and is no longer accurate when the format has been customised.

wagtail/wagtailcore/migrations/0033_remove_golive_expiry_help_text.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.6 on 2017-03-31 14:33
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('wagtailcore', '0032_add_bulk_delete_page_permission'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='page',
+            name='expire_at',
+            field=models.DateTimeField(blank=True, null=True, verbose_name='expiry date/time'),
+        ),
+        migrations.AlterField(
+            model_name='page',
+            name='go_live_at',
+            field=models.DateTimeField(blank=True, null=True, verbose_name='go live date/time'),
+        ),
+    ]

wagtail/wagtailcore/models.py

@@ -302,13 +302,11 @@ class Page(six.with_metaclass(PageBase, AbstractPage, index.Indexed, Clusterable
 
     go_live_at = models.DateTimeField(
         verbose_name=_("go live date/time"),
-        help_text=_("Please add a date-time in the form YYYY-MM-DD hh:mm."),
         blank=True,
         null=True
     )
     expire_at = models.DateTimeField(
         verbose_name=_("expiry date/time"),
-        help_text=_("Please add a date-time in the form YYYY-MM-DD hh:mm."),
         blank=True,
         null=True
     )