diff --git a/grafanimate/model.py b/grafanimate/model.py
index 10aad16..20cae38 100644
--- a/grafanimate/model.py
+++ b/grafanimate/model.py
@@ -6,6 +6,7 @@
 from datetime import datetime, timezone
 from enum import Enum
 from typing import Generator, List, Optional, Union
+from grafanimate.timeutil import RecurrenceInfo
 
 from dateutil.rrule import rrule
 
@@ -30,7 +31,8 @@ def __init__(
         self,
         start: Union[datetime, int, str],
         stop: Union[datetime, int, str],
-        every: str,
+        every: str = None,
+        recurrence: RecurrenceInfo = None,
         mode: Optional[SequencingMode] = SequencingMode.WINDOW,
     ):
 
@@ -45,7 +47,10 @@ def __init__(
 
         # Analyze `every` parameter and converge into `RecurrenceInfo`.
         # From `every` (interval designator), compute frequency, interval and delta.
-        self.recurrence = get_freq_delta(every)
+        if recurrence is not None:
+            self.recurrence = recurrence
+        else:
+            self.recurrence = get_freq_delta(every)
 
         self.mode = mode
         self.index = None
diff --git a/grafanimate/timeutil.py b/grafanimate/timeutil.py
index 9c21e52..d6ba4e3 100644
--- a/grafanimate/timeutil.py
+++ b/grafanimate/timeutil.py
@@ -17,9 +17,6 @@ class RecurrenceInfo:
     For feeding data to `dateutil.rrule.rrule`.
     """
 
-    # Original interval/windowing label.
-    every: str
-
     # One of `rrules`s DAILY, HOURLY, ...
     frequency: int
 
@@ -29,6 +26,9 @@ class RecurrenceInfo:
     # The segment duration, expressed as `relativedelta`.
     duration: relativedelta
 
+    # Original interval/windowing label.
+    every: str = None
+
 
 @dataclasses.dataclass
 class Timerange: