diff --git a/sigmf/utils.py b/sigmf/utils.py
index 5f54e1f..10989e2 100644
--- a/sigmf/utils.py
+++ b/sigmf/utils.py
@@ -10,6 +10,7 @@
 from datetime import datetime
 import sys
 import numpy as np
+import re
 
 from . import error
 
@@ -30,6 +31,12 @@ def parse_iso8601_datetime(datestr: str) -> datetime:
     >>> parse_iso8601_datetime("1955-11-05T06:15:00Z")
     datetime.datetime(1955, 11, 5, 6, 15)
     """
+    m = re.match(r'^(?P<dt>.*)(?P<frac>\.[0-9]{7,})Z$', datestr)
+    if m:
+        d =  m.groupdict()
+        l = min(7, len(d['frac']))
+        datestr = ''.join([d['dt'], d['frac'][:l], 'Z'])
+
     try:
         timestamp = datetime.strptime(datestr, '%Y-%m-%dT%H:%M:%S.%fZ')
     except ValueError:
diff --git a/tests/test_utils.py b/tests/test_utils.py
new file mode 100644
index 0000000..fac1937
--- /dev/null
+++ b/tests/test_utils.py
@@ -0,0 +1,17 @@
+import datetime
+
+import pytest
+
+from sigmf import utils
+
+@pytest.mark.parametrize('ts,expected', [
+    ('1955-08-05T06:15:00Z',                datetime.datetime(year=1955, month=8 , day=5, hour=6 , minute=15, second=00, microsecond=0)),
+    ('1956-09-06T07:15:12Z',                datetime.datetime(year=1956, month=9 , day=6, hour=7 , minute=15, second=12, microsecond=0)),
+    ('1957-10-07T08:15:12.345Z',            datetime.datetime(year=1957, month=10, day=7, hour=8 , minute=15, second=12, microsecond=345000)),
+    ('1958-11-08T09:15:12.0345Z',           datetime.datetime(year=1958, month=11, day=8, hour=9 , minute=15, second=12, microsecond=34500)),
+    ('1959-12-09T10:15:12.000000Z',         datetime.datetime(year=1959, month=12, day=9, hour=10, minute=15, second=12, microsecond=0)),
+    ('1959-12-09T10:15:12.123456789123Z',   datetime.datetime(year=1959, month=12, day=9, hour=10, minute=15, second=12, microsecond=123456)),
+])
+def test_parse_simple_iso8601(ts, expected):
+    dt = utils.parse_iso8601_datetime(ts)
+    assert dt == expected