diff --git a/tests/xapian_backend.py b/tests/xapian_backend.py
index cfa05a5..7338248 100644
--- a/tests/xapian_backend.py
+++ b/tests/xapian_backend.py
@@ -191,8 +191,8 @@ class XapianSearchBackendTestCase(TestCase):
         self.sb.update(self.msi, self.sample_objs)
         self.assertEqual(len(self.xapian_search('')), 3)
 
-        self.assertEqual(self.sb.search('', date_facets={'pub_date': {'start_date': datetime.datetime(2008, 10, 26), 'end_date': datetime.datetime(2009, 3, 26), 'gap': 'month=1'}}), {'hits': 0, 'results': []})
-        results = self.sb.search('index', date_facets={'pub_date': {'start_date': datetime.datetime(2008, 10, 26), 'end_date': datetime.datetime(2009, 3, 26), 'gap': 'month=1'}})
+        self.assertEqual(self.sb.search('', date_facets={'pub_date': {'start_date': datetime.datetime(2008, 10, 26), 'end_date': datetime.datetime(2009, 3, 26), 'gap_by': 'month'}}), {'hits': 0, 'results': []})
+        results = self.sb.search('index', date_facets={'pub_date': {'start_date': datetime.datetime(2008, 10, 26), 'end_date': datetime.datetime(2009, 3, 26), 'gap_by': 'month'}})
         self.assertEqual(results['hits'], 3)
         self.assertEqual(results['facets']['dates']['pub_date'], [
             ('2009-02-26T00:00:00', 0),
@@ -202,7 +202,7 @@ class XapianSearchBackendTestCase(TestCase):
             ('2008-10-26T00:00:00', 0),
         ])
 
-        results = self.sb.search('index', date_facets={'pub_date': {'start_date': datetime.datetime(2009, 02, 01), 'end_date': datetime.datetime(2009, 3, 15), 'gap': 'days=15'}})
+        results = self.sb.search('index', date_facets={'pub_date': {'start_date': datetime.datetime(2009, 02, 01), 'end_date': datetime.datetime(2009, 3, 15), 'gap_by': 'day', 'gap_amount': 15}})
         self.assertEqual(results['hits'], 3)
         self.assertEqual(results['facets']['dates']['pub_date'], [
             ('2009-03-03T00:00:00', 0),
diff --git a/xapian_backend.py b/xapian_backend.py
index 2b94f4e..d3b7db5 100644
--- a/xapian_backend.py
+++ b/xapian_backend.py
@@ -42,8 +42,6 @@ DOCUMENT_ID_TERM_PREFIX = 'Q'
 DOCUMENT_CUSTOM_TERM_PREFIX = 'X'
 DOCUMENT_CT_TERM_PREFIX = DOCUMENT_CUSTOM_TERM_PREFIX + 'CONTENTTYPE'
 
-gap_re = re.compile(r'(?P<type>year|month|day|hour|minute|second+)s?=?(?P<value>\d*)', re.IGNORECASE)
-
 
 class XHValueRangeProcessor(xapian.ValueRangeProcessor):
     def __init__(self, sb):
@@ -525,12 +523,12 @@ class SearchBackend(BaseSearchBackend):
         Required arguments:
             `results` -- A list SearchResults to facet
             `date_facets` -- A dictionary containing facet parameters:
-                {'field': {'start_date': ..., 'end_date': ...: 'gap': '...'}}
-                nb., gap must satisfy the regex:
-                    (?P<type>year|month|day|hour|minute|second+)s?=?(?P<value>\d*)
+                {'field': {'start_date': ..., 'end_date': ...: 'gap_by': '...', 'gap_amount': n}}
+                nb., gap must be one of the following:
+                    year|month|day|hour|minute|second
         
         For each date facet field in `date_facets`, generates a list
-        of date ranges (from `start_date` to `end_date` by `gap`) then
+        of date ranges (from `start_date` to `end_date` by `gap_by`) then
         iterates through `results` and tallies the count for each date_facet.
         
         Returns a dictionary of date facets (fields) containing a list with
@@ -549,9 +547,8 @@ class SearchBackend(BaseSearchBackend):
         facet_dict = {}
         
         for date_facet, facet_params in date_facets.iteritems():
-            match = gap_re.search(facet_params['gap']).groupdict()
-            gap_type = match['type']
-            gap_value = match.get('value', 1)
+            gap_type = facet_params.get('gap_by')
+            gap_value = facet_params.get('gap_amount', 1)
             date_range = facet_params['start_date']
             facet_list = []
             while date_range < facet_params['end_date']: