diff --git a/mica/archive/aca_dark/dark_cal.py b/mica/archive/aca_dark/dark_cal.py
index 90c9f613..bcc3ed7d 100644
--- a/mica/archive/aca_dark/dark_cal.py
+++ b/mica/archive/aca_dark/dark_cal.py
@@ -104,7 +104,11 @@ def get_dark_cal_id(date, select='before'):
 
     :returns: dark cal id string (YYYYDOY)
     """
-    return _get_dark_cal_id_vector(date, select=select)
+    dark_id = _get_dark_cal_id_vector(date, select=select)
+    if not dark_id.shape:
+        # returning an instance of the type, not a numpy array
+        return dark_id.tolist()
+    return dark_id
 
 
 def _get_dark_cal_id_scalar(date, select='before'):
diff --git a/mica/archive/tests/test_aca_dark_cal.py b/mica/archive/tests/test_aca_dark_cal.py
index 479d3e31..c2e70048 100644
--- a/mica/archive/tests/test_aca_dark_cal.py
+++ b/mica/archive/tests/test_aca_dark_cal.py
@@ -109,6 +109,12 @@ def test_get_dark_cal_props_table_mixed():
                               'n_ccd_img', 'datestart', 'datestop', 'filename']
 
 
+@pytest.mark.skipif('not HAS_DARK_ARCHIVE', reason='Test requires dark archive')
+def test_scalar():
+    dark_cal_id = dark_cal.get_dark_cal_id('2022:100')
+    assert dark_cal_id[:4] == '2022' and dark_cal_id[4:] == '069'
+
+
 @pytest.mark.skipif('not HAS_DARK_ARCHIVE', reason='Test requires dark archive')
 def test_vectorized():
     dark_id_ref = ['2022100', '2022105', '2022127']