diff --git a/import2ledger/importers/nbpy2017.py b/import2ledger/importers/nbpy2017.py
index 9e35eb6..31927c2 100644
--- a/import2ledger/importers/nbpy2017.py
+++ b/import2ledger/importers/nbpy2017.py
@@ -63,7 +63,7 @@ class Invoice2017:
         self.actions
 
     def _strpdate(self, s):
-        date_s = strparse.rejoin_slice_words(s, slice(2), ',', 2)
+        date_s = strparse.rejoin_slice_words(s, slice(2), ',', 2).replace('Sept.', 'Sep.')
         return strparse.date(date_s, '%b. %d, %Y')
 
     def _read_invoice_header(self, table, first_row_text, rows_text):
diff --git a/tests/data/imports.yml b/tests/data/imports.yml
index b0216d7..41dd760 100644
--- a/tests/data/imports.yml
+++ b/tests/data/imports.yml
@@ -237,7 +237,7 @@
   expect:
     - payee: Python Person C
       ledger template: nbpy2017 invoice ledger entry
-      date: !!python/object/apply:datetime.date [2017, 10, 5]
+      date: !!python/object/apply:datetime.date [2017, 9, 5]
       amount: !!python/object/apply:decimal.Decimal ["55.00"]
       tickets_sold: !!python/object/apply:decimal.Decimal ["1"]
       ticket_rate: !!python/object/apply:decimal.Decimal ["21.25"]
@@ -245,11 +245,11 @@
       shirt_rate: !!python/object/apply:decimal.Decimal ["25.50"]
       status: Invoice
       currency: USD
-      invoice_date: !!python/object/apply:datetime.date [2017, 10, 5]
+      invoice_date: !!python/object/apply:datetime.date [2017, 9, 5]
       invoice_id: "11"
     - payee: Python Person C
       ledger template: nbpy2017 payment ledger entry
-      date: !!python/object/apply:datetime.date [2017, 10, 5]
+      date: !!python/object/apply:datetime.date [2017, 9, 5]
       amount: !!python/object/apply:decimal.Decimal ["55.00"]
       tickets_sold: !!python/object/apply:decimal.Decimal ["1"]
       ticket_rate: !!python/object/apply:decimal.Decimal ["21.25"]
@@ -257,7 +257,7 @@
       shirt_rate: !!python/object/apply:decimal.Decimal ["25.50"]
       status: Payment
       currency: USD
-      invoice_date: !!python/object/apply:datetime.date [2017, 10, 5]
+      invoice_date: !!python/object/apply:datetime.date [2017, 9, 5]
       payment_id: ch_daer0ahwoh9oDeiqu2eimoD7
       stripe_id: ch_daer0ahwoh9oDeiqu2eimoD7
       invoice_id: "11"
diff --git a/tests/data/nbpy2017c.html b/tests/data/nbpy2017c.html
index 72734a9..fb7ed95 100644
--- a/tests/data/nbpy2017c.html
+++ b/tests/data/nbpy2017c.html
@@ -155,8 +155,8 @@
     <table class="table">
       <tr><th>Number</th><td> 11</td></tr>
       <tr><th>Status</th><td> Refunded</td></tr>
-      <tr><th>Issue date</th><td> Oct. 5, 2017</td></tr>
-        <tr><th>Due</th><td> Oct. 6, 2017, 9:09 p.m.</td></tr>
+      <tr><th>Issue date</th><td> Sept. 5, 2017</td></tr>
+        <tr><th>Due</th><td> Sept. 6, 2017, 9:09 p.m.</td></tr>
       <tr><th>Recipient</th><td> Python Person C<br />Anycountry</td></tr>
     </table>
   <div class="panel-body">
@@ -225,12 +225,12 @@
       <th>Amount</th>
     </tr>
       <tr>
-        <td>Oct. 5, 2017, 9:14 p.m.</td>
+        <td>Sept. 5, 2017, 9:14 p.m.</td>
         <td>Paid with Stripe reference: ch_daer0ahwoh9oDeiqu2eimoD7</td>
         <td>55.00</td>
       </tr>
       <tr>
-        <td>Oct. 8, 2017, 3:20 p.m.</td>
+        <td>Sept. 8, 2017, 3:20 p.m.</td>
         <td>Generated credit note 31</td>
         <td>-55.00</td>
       </tr>