diff --git a/requirements-nover.txt b/requirements-nover.txt
index 3898df463..786792fb5 100644
--- a/requirements-nover.txt
+++ b/requirements-nover.txt
@@ -62,4 +62,3 @@ bencode
 cryptography
 httmock
 moto
-timeparse
diff --git a/requirements.txt b/requirements.txt
index 1e2557ac8..2d81b6b60 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -107,7 +107,6 @@ SQLAlchemy==1.0.12
 stevedore==1.12.0
 stringscore==0.1.0
 stripe==1.32.0
-timeparse==0.5.5
 toposort==1.4
 trollius==2.1
 tzlocal==1.2.2
diff --git a/util/generatepresharedkey.py b/util/generatepresharedkey.py
index 4343deb51..99b5eff22 100644
--- a/util/generatepresharedkey.py
+++ b/util/generatepresharedkey.py
@@ -1,10 +1,12 @@
+import argparse
+
+from dateutil.parser import parse as parse_date
+
 from app import app
 from data import model
 from data.database import ServiceKeyApprovalType
 from data.model.log import log_action
-from timeparse import ParseDatetime
 
-import argparse
 
 def generate_key(service, name, expiration_date=None, notes=None):
   metadata = {
@@ -34,12 +36,20 @@ def generate_key(service, name, expiration_date=None, notes=None):
   return private_key, key.kid
 
 
+def valid_date(s):
+  try:
+    return parse_date(s)
+  except ValueError:
+    msg = "Not a valid date: '{0}'.".format(s)
+    raise argparse.ArgumentTypeError(msg)
+
+
 if __name__ == '__main__':
   parser = argparse.ArgumentParser(description='Generates a preshared key')
   parser.add_argument('service', help='The service name for which the key is being generated')
   parser.add_argument('name', help='The friendly name for the key')
-  parser.add_argument('--expiration', help='The optional expiration date/time for the key',
-                      default=None, action=ParseDatetime)
+  parser.add_argument('--expiration', default=None, type=valid_date,
+                      help='The optional expiration date for the key')
   parser.add_argument('--notes', help='Optional notes about the key', default=None)
 
   args = parser.parse_args()