diff --git a/ietf/bin/fix-ambiguous-document-timestamps b/ietf/bin/fix-ambiguous-document-timestamps
deleted file mode 100755
index 2436e9303..000000000
--- a/ietf/bin/fix-ambiguous-document-timestamps
+++ /dev/null
@@ -1,51 +0,0 @@
-#!/usr/bin/env python
-# -*- Python -*-
-
-"""
-This script looks at document timestamps going back three years, and if it finds
-ambiguous timestamps, shifts them backwards one hour in order to disambiguate
-them.
-"""
-
-import os, sys
-import datetime
-import pytz
-
-filename = os.path.abspath(__file__)
-basedir = os.path.abspath(os.path.join(os.path.dirname(__file__), "../.."))
-sys.path = [ basedir ] + sys.path
-os.environ["DJANGO_SETTINGS_MODULE"] = "ietf.settings"
-
-virtualenv_activation = os.path.join(basedir, "env", "bin", "activate_this.py")
-if os.path.exists(virtualenv_activation):
-    execfile(virtualenv_activation, dict(__file__=virtualenv_activation))
-
-import django
-django.setup()
-
-from django.conf import settings
-from ietf.doc.models import Document, DocEvent
-
-now = datetime.datetime.now()
-then = now - datetime.timedelta(days=365*3)
-
-for d in Document.objects.filter(time__gt=then).order_by('-time'):
-    tz = pytz.timezone(settings.TIME_ZONE)
-    try:
-        t = tz.localize(d.time, is_dst=None)
-    except pytz.AmbiguousTimeError as e:
-        orig = d.time
-        d.time = d.time - datetime.timedelta(minutes=60)
-        print "%s:\n  changed %s --> %s" % (d, orig, d.time)
-        d.save()
-
-for d in DocEvent.objects.filter(time__gt=then).order_by('-time'):
-    tz = pytz.timezone(settings.TIME_ZONE)
-    try:
-        t = tz.localize(d.time, is_dst=None)
-    except pytz.AmbiguousTimeError as e:
-        orig = d.time
-        d.time = d.time - datetime.timedelta(minutes=60)
-        print "%s:\n  changed %s --> %s" % (d, orig, d.time)
-        d.save()
-        
diff --git a/ietf/bin/fix-ambiguous-timestamps b/ietf/bin/fix-ambiguous-timestamps
new file mode 100755
index 000000000..b7d64d369
--- /dev/null
+++ b/ietf/bin/fix-ambiguous-timestamps
@@ -0,0 +1,89 @@
+#!/usr/bin/env python
+# Copyright The IETF Trust 2016-2018, All Rights Reserved
+# -*- Python -*-
+
+"""
+This script looks at document timestamps going back 14 days, and if it finds
+ambiguous timestamps, shifts them one hour in order to disambiguate
+them.
+"""
+from __future__ import unicode_literals, print_function
+
+
+import os, sys
+import datetime
+import pytz
+import debug
+import tqdm
+
+filename = os.path.abspath(__file__)
+basedir = os.path.abspath(os.path.join(os.path.dirname(__file__), "../.."))
+sys.path = [ basedir ] + sys.path
+os.environ["DJANGO_SETTINGS_MODULE"] = "ietf.settings"
+
+virtualenv_activation = os.path.join(basedir, "env", "bin", "activate_this.py")
+if os.path.exists(virtualenv_activation):
+    execfile(virtualenv_activation, dict(__file__=virtualenv_activation))
+
+import django
+django.setup()
+
+from django.conf import settings
+from django.contrib.auth.models import User
+from ietf.doc.models import Document, DocEvent, DocHistory
+from ietf.mailinglists.models import Subscribed
+from ietf.meeting.models import SchedTimeSessAssignment, Session
+from ietf.message.models import Message
+from ietf.person.models import Person, HistoricalEmail, HistoricalPerson
+from ietf.submit.models import SubmissionCheck, SubmissionEvent
+
+
+now = datetime.datetime.now()
+then = now - datetime.timedelta(days=30)
+by = Person.objects.get(name='(System)')
+tz = pytz.timezone(settings.TIME_ZONE)
+
+def fixup(Model, field, start, stop):
+    lookup = {
+        '%s__gt'%field: start,
+        '%s__lt'%field: stop,
+        }
+    print("%s.%s:" % (Model.__name__, field))
+    for d in Model.objects.filter(**lookup).order_by('-%s'%field):
+        orig = getattr(d, field)
+        try:
+            tz.localize(orig, is_dst=None)
+        except pytz.AmbiguousTimeError as e:
+            new = orig-datetime.timedelta(minutes=60)
+            setattr(d, field, new)
+            desc = "  %s: changed ambiguous time:  %s --> %s" % (d.pk, orig, new)
+            print(desc)
+            if Model.__name__ == 'Document':
+                e = DocEvent(type='added_comment', doc=d, rev=d.rev, by=by, desc=desc)
+                e.save()
+                d.save_with_history([e])
+            else:
+                d.save()
+
+time_fields = (
+        (DocEvent, 'time'),
+        (DocHistory, 'time'),
+        (Document, 'time'),
+        (HistoricalEmail, 'time'),
+        (HistoricalPerson, 'time'),
+        (Message, 'time'),
+        (SchedTimeSessAssignment, 'modified'),
+        (Session, 'requested'),
+        (Session, 'scheduled'),
+        (Session, 'modified'),
+        (SubmissionCheck, 'time'),
+        (SubmissionEvent, 'time'),
+        (Subscribed, 'time'),
+        (User, 'date_joined'),
+    )
+
+for Model, field in time_fields:
+    stop = datetime.datetime.now()
+    start = stop - datetime.timedelta(days=14)
+    fixup(Model, field, start, stop)
+