diff --git a/scripts/make_checkpoint.py b/scripts/make_checkpoint.py
index 85744709..d690826b 100644
--- a/scripts/make_checkpoint.py
+++ b/scripts/make_checkpoint.py
@@ -7,7 +7,7 @@
 import os.path
 import random
 import sys
-from datetime import datetime
+from datetime import datetime, timezone
 
 from whoosh import fields, index
 from whoosh.compat import u
@@ -46,7 +46,12 @@
             frac += 0.15
             path = u(f"{segnum}/{num}")
             title = " ".join(random.choice(words) for _ in range(100))
-            dt = datetime(year=2000 + counter, month=(counter % 12) + 1, day=15)
+            dt = datetime(
+                year=2000 + counter,
+                month=(counter % 12) + 1,
+                day=15,
+                tzinfo=timezone.utc,
+            )
 
             w.add_document(
                 path=path,
diff --git a/src/whoosh/qparser/dateparse.py b/src/whoosh/qparser/dateparse.py
index 6a29b252..35552c17 100644
--- a/src/whoosh/qparser/dateparse.py
+++ b/src/whoosh/qparser/dateparse.py
@@ -27,7 +27,7 @@
 
 import re
 import sys
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
 from whoosh.compat import iteritems, string_type
 from whoosh.qparser import plugins, syntax
@@ -89,7 +89,7 @@ def parse(self, text, dt, pos=0, debug=-9999):
 
     def date_from(self, text, dt=None, pos=0, debug=-9999):
         if dt is None:
-            dt = datetime.now()
+            dt = datetime.now(tz=timezone.utc)
 
         d, pos = self.parse(text, dt, pos, debug + 1)
         return d
@@ -661,7 +661,7 @@ def parse(self, text, dt, pos=0, debug=-9999):
 
     def date_from(self, text, basedate=None, pos=0, debug=-9999, toend=True):
         if basedate is None:
-            basedate = datetime.utcnow()
+            basedate = datetime.now(tz=timezone.utc)
 
         parser = self.get_parser()
         if toend:
diff --git a/src/whoosh/util/times.py b/src/whoosh/util/times.py
index 55df3e1d..fff02d54 100644
--- a/src/whoosh/util/times.py
+++ b/src/whoosh/util/times.py
@@ -27,7 +27,7 @@
 
 import calendar
 import copy
-from datetime import date, datetime, timedelta
+from datetime import date, datetime, timedelta, timezone
 
 from whoosh.compat import iteritems
 
@@ -171,7 +171,7 @@ def tuple(self):
         )
 
     def date(self):
-        return date(self.year, self.month, self.day)
+        return date(self.year, self.month, self.day, tzinfo=timezone.utc)
 
     def copy(self):
         return adatetime(
@@ -237,7 +237,7 @@ def floor(self):
             s = 0
         if ms is None:
             ms = 0
-        return datetime(y, m, d, h, mn, s, ms)
+        return datetime(y, m, d, h, mn, s, ms, tzinfo=timezone.utc)
 
     def ceil(self):
         """Returns a ``datetime`` version of this object with all unspecified
@@ -275,7 +275,7 @@ def ceil(self):
             s = 59
         if ms is None:
             ms = 999999
-        return datetime(y, m, d, h, mn, s, ms)
+        return datetime(y, m, d, h, mn, s, ms, tzinfo=timezone.utc)
 
     def disambiguated(self, basedate):
         """Returns either a ``datetime`` or unambiguous ``timespan`` version
@@ -514,4 +514,5 @@ def fix(at):
         minute=at.minute,
         second=at.second,
         microsecond=at.microsecond,
+        tzinfo=timezone.utc,
     )
diff --git a/stress/test_bigsort.py b/stress/test_bigsort.py
index e28efa31..b25b9007 100644
--- a/stress/test_bigsort.py
+++ b/stress/test_bigsort.py
@@ -1,7 +1,7 @@
 import os.path
 import random
 import shutil
-from datetime import datetime
+from datetime import datetime, timezone
 
 from whoosh import fields, index, query
 from whoosh.compat import text_type
@@ -24,7 +24,9 @@ def test_bigsort():
     t = now()
     w = ix.writer(limitmb=512)
     for i in range(times):
-        dt = datetime.fromtimestamp(random.randint(15839593, 1294102139))
+        dt = datetime.fromtimestamp(
+            random.randint(15839593, 1294102139), tz=timezone.utc
+        )
         w.add_document(id=text_type(i), date=dt)
     w.commit()
     print("Writing took ", now() - t)
diff --git a/tests/test_dateparse.py b/tests/test_dateparse.py
index a87e5e20..9acba143 100644
--- a/tests/test_dateparse.py
+++ b/tests/test_dateparse.py
@@ -1,4 +1,4 @@
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
 from whoosh.qparser.dateparse import (
     English,
@@ -8,7 +8,7 @@
     timespan,
 )
 
-basedate = datetime(2010, 9, 20, 15, 16, 6, 454000)
+basedate = datetime(2010, 9, 20, 15, 16, 6, 454000, tzinfo=timezone.utc)
 english = English()
 
 
diff --git a/tests/test_fields.py b/tests/test_fields.py
index dae12205..47acff8e 100644
--- a/tests/test_fields.py
+++ b/tests/test_fields.py
@@ -1,4 +1,4 @@
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
 import pytest
 from whoosh import fields, qparser, query
@@ -340,7 +340,7 @@ def test_nontext_document():
     )
     ix = RamStorage().create_index(schema)
 
-    dt = datetime.now()
+    dt = datetime.now(tz=timezone.utc)
     w = ix.writer()
     for i in range(50):
         w.add_document(id=i, num=i, date=dt + timedelta(days=i), even=not (i % 2))
@@ -365,7 +365,7 @@ def test_nontext_update():
     )
     ix = RamStorage().create_index(schema)
 
-    dt = datetime.now()
+    dt = datetime.now(tz=timezone.utc)
     w = ix.writer()
     for i in range(10):
         w.add_document(id=i, num=i, date=dt + timedelta(days=i))
@@ -391,7 +391,8 @@ def test_datetime():
     for month in range(1, 12):
         for day in range(1, 28):
             w.add_document(
-                id=u("%s-%s") % (month, day), date=datetime(2010, month, day, 14, 0, 0)
+                id=u("%s-%s") % (month, day),
+                date=datetime(2010, month, day, 14, 0, 0, tzinfo=timezone.utc),
             )
     w.commit()
 
@@ -409,8 +410,8 @@ def test_datetime():
         assert len(r) == 27
 
         q = qp.parse(u("date:[2010-05 to 2010-08]"))
-        startdt = datetime(2010, 5, 1, 0, 0, 0, 0)
-        enddt = datetime(2010, 8, 31, 23, 59, 59, 999999)
+        startdt = datetime(2010, 5, 1, 0, 0, 0, 0, tzinfo=timezone.utc)
+        enddt = datetime(2010, 8, 31, 23, 59, 59, 999999, tzinfo=timezone.utc)
         assert q.__class__ is query.NumericRange
         assert q.start == times.datetime_to_long(startdt)
         assert q.end == times.datetime_to_long(enddt)
@@ -694,9 +695,11 @@ def test_valid_date_string():
     query = field.parse_query("date", date_string)
 
     # Define the expected start and end dates
-    expected_start = datetime_to_long(datetime.datetime(2022, 1, 1))
+    expected_start = datetime_to_long(
+        datetime.datetime(2022, 1, 1, tzinfo=timezone.utc)
+    )
     expected_end = datetime_to_long(
-        datetime.datetime(2022, 1, 1)
+        datetime.datetime(2022, 1, 1, tzinfo=timezone.utc)
         + datetime.timedelta(days=1)
         - datetime.timedelta(microseconds=1)
     )
diff --git a/tests/test_indexing.py b/tests/test_indexing.py
index e91cb7d2..01c1fb07 100644
--- a/tests/test_indexing.py
+++ b/tests/test_indexing.py
@@ -1,6 +1,6 @@
 import random
 from collections import defaultdict
-from datetime import datetime
+from datetime import datetime, timezone
 
 import pytest
 from whoosh import __version__, analysis, fields, index, qparser, query
@@ -629,15 +629,20 @@ def test_multivalue():
     )
     ix = RamStorage().create_index(schema)
     with ix.writer() as w:
-        w.add_document(id=1, date=datetime(2001, 1, 1), num=5)
+        w.add_document(id=1, date=datetime(2001, 1, 1, tzinfo=timezone.utc), num=5)
         w.add_document(
-            id=2, date=[datetime(2002, 2, 2), datetime(2003, 3, 3)], num=[1, 2, 3, 12]
+            id=2,
+            date=[
+                datetime(2002, 2, 2, tzinfo=timezone.utc),
+                datetime(2003, 3, 3, tzinfo=timezone.utc),
+            ],
+            num=[1, 2, 3, 12],
         )
         w.add_document(txt=u("a b c").split())
 
     with ix.reader() as r:
         assert ("num", 3) in r
-        assert ("date", datetime(2003, 3, 3)) in r
+        assert ("date", datetime(2003, 3, 3, tzinfo=timezone.utc)) in r
         assert " ".join(r.field_terms("txt")) == "a b c"
 
 
diff --git a/tests/test_matching.py b/tests/test_matching.py
index f817e576..295d80df 100644
--- a/tests/test_matching.py
+++ b/tests/test_matching.py
@@ -500,12 +500,12 @@ def test_dismax():
 
 
 def test_exclusion():
-    from datetime import datetime
+    from datetime import datetime, timezone
 
     schema = fields.Schema(id=fields.ID(stored=True), date=fields.DATETIME)
     ix = RamStorage().create_index(schema)
-    dt1 = datetime(1950, 1, 1)
-    dt2 = datetime(1960, 1, 1)
+    dt1 = datetime(1950, 1, 1, tzinfo=timezone.utc)
+    dt2 = datetime(1960, 1, 1, tzinfo=timezone.utc)
     with ix.writer() as w:
         # Make 39 documents with dates != dt1 and then make a last document
         # with feed == dt1.
diff --git a/tests/test_parse_plugins.py b/tests/test_parse_plugins.py
index a3058d6a..eecfbe00 100644
--- a/tests/test_parse_plugins.py
+++ b/tests/test_parse_plugins.py
@@ -1,5 +1,5 @@
 import inspect
-from datetime import datetime
+from datetime import datetime, timezone
 
 from whoosh import analysis, fields, formats, qparser, query
 from whoosh.compat import text_type, u
@@ -69,7 +69,7 @@ def test_dateparser():
     def cb(arg):
         errs.append(arg)
 
-    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000)
+    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000, tzinfo=timezone.utc)
     qp.add_plugin(dateparse.DateParserPlugin(basedate, callback=cb))
 
     q = qp.parse(u("hello date:'last tuesday'"))
@@ -118,7 +118,7 @@ def cb(arg):
 def test_date_range():
     schema = fields.Schema(text=fields.TEXT, date=fields.DATETIME)
     qp = qparser.QueryParser("text", schema)
-    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000)
+    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000, tzinfo=timezone.utc)
     qp.add_plugin(dateparse.DateParserPlugin(basedate))
 
     q = qp.parse(u("date:['30 march' to 'next wednesday']"))
@@ -155,7 +155,7 @@ def test_date_range():
 def test_daterange_multi():
     schema = fields.Schema(text=fields.TEXT, start=fields.DATETIME, end=fields.DATETIME)
     qp = qparser.QueryParser("text", schema)
-    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000)
+    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000, tzinfo=timezone.utc)
     qp.add_plugin(dateparse.DateParserPlugin(basedate))
 
     q = qp.parse("start:[2008 to] AND end:[2011 to 2011]")
@@ -177,7 +177,11 @@ def test_daterange_empty_field():
     writer.commit()
 
     with ix.searcher() as s:
-        q = query.DateRange("test", datetime.fromtimestamp(86400), datetime.today())
+        q = query.DateRange(
+            "test",
+            datetime.fromtimestamp(86400, tz=timezone.utc),
+            datetime.now(tz=timezone.utc),
+        )
         r = s.search(q)
         assert len(r) == 0
 
@@ -186,7 +190,7 @@ def test_free_dates():
     a = analysis.StandardAnalyzer(stoplist=None)
     schema = fields.Schema(text=fields.TEXT(analyzer=a), date=fields.DATETIME)
     qp = qparser.QueryParser("text", schema)
-    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000)
+    basedate = datetime(2010, 9, 20, 15, 16, 6, 454000, tzinfo=timezone.utc)
     qp.add_plugin(dateparse.DateParserPlugin(basedate, free=True))
 
     q = qp.parse(u("hello date:last tuesday"))
@@ -366,7 +370,9 @@ def test_gtlt():
     assert len(q) == 3
     assert q[0] == query.Term("a", "hello")
     # As of this writing, date ranges don't support startexcl/endexcl
-    assert q[1] == query.DateRange("e", datetime(2001, 3, 29, 0, 0), None)
+    assert q[1] == query.DateRange(
+        "e", datetime(2001, 3, 29, 0, 0, tzinfo=timezone.utc), None
+    )
     assert q[2] == query.Term("a", "there")
 
     q = qp.parse(u("a:> alfa c:<= bravo"))
diff --git a/tests/test_queries.py b/tests/test_queries.py
index a8a7558f..b9a6090e 100644
--- a/tests/test_queries.py
+++ b/tests/test_queries.py
@@ -397,7 +397,7 @@ def test_requires():
 
 
 def test_highlight_daterange():
-    from datetime import datetime
+    from datetime import datetime, timezone
 
     schema = fields.Schema(
         id=fields.ID(unique=True, stored=True),
@@ -412,7 +412,7 @@ def test_highlight_daterange():
         id=u("1"),
         title=u("Life Aquatic"),
         content=u("A nautic film crew sets out to kill a gigantic shark."),
-        released=datetime(2004, 12, 25),
+        released=datetime(2004, 12, 25, tzinfo=timezone.utc),
     )
     w.update_document(
         id=u("2"),
@@ -420,7 +420,7 @@ def test_highlight_daterange():
         content=u(
             "Three brothers meet in India for a life changing train " + "journey."
         ),
-        released=datetime(2007, 10, 27),
+        released=datetime(2007, 10, 27, tzinfo=timezone.utc),
     )
     w.commit()
 
@@ -433,7 +433,7 @@ def test_highlight_daterange():
         == 'for a life changing <b class="match term0">train</b> journey'
     )
 
-    r = s.search(DateRange("released", datetime(2007, 1, 1), None))
+    r = s.search(DateRange("released", datetime(2007, 1, 1, tzinfo=timezone.utc), None))
     assert len(r) == 1
     assert r[0].highlights("content") == ""
 
diff --git a/tests/test_searching.py b/tests/test_searching.py
index d76c8094..3b4c7e56 100644
--- a/tests/test_searching.py
+++ b/tests/test_searching.py
@@ -1,5 +1,5 @@
 import copy
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
 import pytest
 from whoosh import analysis, fields, index, qparser, query, scoring
@@ -366,7 +366,7 @@ def test_open_numeric_ranges():
 
 
 def test_open_date_ranges():
-    basedate = datetime(2011, 1, 24, 6, 25, 0, 0)
+    basedate = datetime(2011, 1, 24, 6, 25, 0, 0, tzinfo=timezone.utc)
     domain = [basedate + timedelta(days=n) for n in range(-20, 20)]
 
     schema = fields.Schema(date=fields.DATETIME(stored=True))
@@ -382,13 +382,17 @@ def test_open_date_ranges():
         q = qp.parse("[2011-01-10 to]")
         r = [hit["date"] for hit in s.search(q, limit=None)]
         assert len(r) > 0
-        target = [d for d in domain if d >= datetime(2011, 1, 10, 6, 25)]
+        target = [
+            d for d in domain if d >= datetime(2011, 1, 10, 6, 25, tzinfo=timezone.utc)
+        ]
         assert r == target
 
         q = qp.parse("[to 2011-01-30]")
         r = [hit["date"] for hit in s.search(q, limit=None)]
         assert len(r) > 0
-        target = [d for d in domain if d <= datetime(2011, 1, 30, 6, 25)]
+        target = [
+            d for d in domain if d <= datetime(2011, 1, 30, 6, 25, tzinfo=timezone.utc)
+        ]
         assert r == target
 
         # With date parser
@@ -399,13 +403,17 @@ def test_open_date_ranges():
         q = qp.parse("[10 jan 2011 to]")
         r = [hit["date"] for hit in s.search(q, limit=None)]
         assert len(r) > 0
-        target = [d for d in domain if d >= datetime(2011, 1, 10, 6, 25)]
+        target = [
+            d for d in domain if d >= datetime(2011, 1, 10, 6, 25, tzinfo=timezone.utc)
+        ]
         assert r == target
 
         q = qp.parse("[to 30 jan 2011]")
         r = [hit["date"] for hit in s.search(q, limit=None)]
         assert len(r) > 0
-        target = [d for d in domain if d <= datetime(2011, 1, 30, 6, 25)]
+        target = [
+            d for d in domain if d <= datetime(2011, 1, 30, 6, 25, tzinfo=timezone.utc)
+        ]
         assert r == target
 
 
@@ -420,7 +428,7 @@ def test_negated_unlimited_ranges():
 
     domain = text_type(ascii_letters)
 
-    dt = datetime.now()
+    dt = datetime.now(tz=timezone.utc)
     for i, letter in enumerate(domain):
         w.add_document(id=letter, num=i, date=dt + timedelta(days=i))
     w.commit()
diff --git a/tests/test_sorting.py b/tests/test_sorting.py
index ac0fd817..2883defd 100644
--- a/tests/test_sorting.py
+++ b/tests/test_sorting.py
@@ -1,5 +1,5 @@
 import random
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
 from whoosh import columns, fields, query, sorting
 from whoosh.compat import permutations, u
@@ -329,8 +329,8 @@ def test_date_facet():
 
     ix = RamStorage().create_index(schema)
     w = ix.writer()
-    d1 = datetime(2011, 7, 13)
-    d2 = datetime(1984, 3, 29)
+    d1 = datetime(2011, 7, 13)  # noqa: DTZ001
+    d2 = datetime(1984, 3, 29)  # noqa: DTZ001
     w.add_document(id=0, date=d1)
     w.add_document(id=1, date=d1)
     w.add_document(id=2)
@@ -392,24 +392,36 @@ def test_daterange_facet():
     schema = fields.Schema(id=fields.STORED, date=fields.DATETIME)
     ix = RamStorage().create_index(schema)
     w = ix.writer()
-    w.add_document(id=0, date=datetime(2001, 1, 15))
-    w.add_document(id=1, date=datetime(2001, 1, 10))
+    w.add_document(id=0, date=datetime(2001, 1, 15, tzinfo=timezone.utc))
+    w.add_document(id=1, date=datetime(2001, 1, 10, tzinfo=timezone.utc))
     w.add_document(id=2)
-    w.add_document(id=3, date=datetime(2001, 1, 3))
-    w.add_document(id=4, date=datetime(2001, 1, 8))
-    w.add_document(id=5, date=datetime(2001, 1, 6))
+    w.add_document(id=3, date=datetime(2001, 1, 3, tzinfo=timezone.utc))
+    w.add_document(id=4, date=datetime(2001, 1, 8, tzinfo=timezone.utc))
+    w.add_document(id=5, date=datetime(2001, 1, 6, tzinfo=timezone.utc))
     w.commit()
 
     with ix.searcher() as s:
         rf = sorting.DateRangeFacet(
-            "date", datetime(2001, 1, 1), datetime(2001, 1, 20), timedelta(days=5)
+            "date",
+            datetime(2001, 1, 1, tzinfo=timezone.utc),
+            datetime(2001, 1, 20, tzinfo=timezone.utc),
+            timedelta(days=5),
         )
         r = s.search(query.Every(), groupedby={"date": rf})
         dt = datetime
         assert r.groups("date") == {
-            (dt(2001, 1, 1, 0, 0), dt(2001, 1, 6, 0, 0)): [3],
-            (dt(2001, 1, 6, 0, 0), dt(2001, 1, 11, 0, 0)): [1, 4, 5],
-            (dt(2001, 1, 11, 0, 0), dt(2001, 1, 16, 0, 0)): [0],
+            (
+                dt(2001, 1, 1, 0, 0, tzinfo=timezone.utc),
+                dt(2001, 1, 6, 0, 0, tzinfo=timezone.utc),
+            ): [3],
+            (
+                dt(2001, 1, 6, 0, 0, tzinfo=timezone.utc),
+                dt(2001, 1, 11, 0, 0, tzinfo=timezone.utc),
+            ): [1, 4, 5],
+            (
+                dt(2001, 1, 11, 0, 0, tzinfo=timezone.utc),
+                dt(2001, 1, 16, 0, 0, tzinfo=timezone.utc),
+            ): [0],
             None: [2],
         }
 
@@ -421,30 +433,68 @@ def test_relative_daterange():
 
     schema = fields.Schema(id=fields.STORED, date=fields.DATETIME)
     ix = RamStorage().create_index(schema)
-    basedate = datetime(2001, 1, 1)
+    basedate = datetime(2001, 1, 1, tzinfo=timezone.utc)
     count = 0
     with ix.writer() as w:
-        while basedate < datetime(2001, 12, 1):
+        while basedate < datetime(2001, 12, 1, tzinfo=timezone.utc):
             w.add_document(id=count, date=basedate)
             basedate += timedelta(days=14, hours=16)
             count += 1
 
     with ix.searcher() as s:
         gap = relativedelta(months=1)
-        rf = sorting.DateRangeFacet("date", dt(2001, 1, 1), dt(2001, 12, 31), gap)
+        rf = sorting.DateRangeFacet(
+            "date",
+            dt(2001, 1, 1, tzinfo=timezone.utc),
+            dt(2001, 12, 31, tzinfo=timezone.utc),
+            gap,
+        )
         r = s.search(query.Every(), groupedby={"date": rf})
         assert r.groups("date") == {
-            (dt(2001, 1, 1), dt(2001, 2, 1)): [0, 1, 2],
-            (dt(2001, 2, 1), dt(2001, 3, 1)): [3, 4],
-            (dt(2001, 3, 1), dt(2001, 4, 1)): [5, 6],
-            (dt(2001, 4, 1), dt(2001, 5, 1)): [7, 8],
-            (dt(2001, 5, 1), dt(2001, 6, 1)): [9, 10],
-            (dt(2001, 6, 1), dt(2001, 7, 1)): [11, 12],
-            (dt(2001, 7, 1), dt(2001, 8, 1)): [13, 14],
-            (dt(2001, 8, 1), dt(2001, 9, 1)): [15, 16],
-            (dt(2001, 9, 1), dt(2001, 10, 1)): [17, 18],
-            (dt(2001, 10, 1), dt(2001, 11, 1)): [19, 20],
-            (dt(2001, 11, 1), dt(2001, 12, 1)): [21, 22],
+            (
+                dt(2001, 1, 1, tzinfo=timezone.utc),
+                dt(2001, 2, 1, tzinfo=timezone.utc),
+            ): [0, 1, 2],
+            (
+                dt(2001, 2, 1, tzinfo=timezone.utc),
+                dt(2001, 3, 1, tzinfo=timezone.utc),
+            ): [3, 4],
+            (
+                dt(2001, 3, 1, tzinfo=timezone.utc),
+                dt(2001, 4, 1, tzinfo=timezone.utc),
+            ): [5, 6],
+            (
+                dt(2001, 4, 1, tzinfo=timezone.utc),
+                dt(2001, 5, 1, tzinfo=timezone.utc),
+            ): [7, 8],
+            (
+                dt(2001, 5, 1, tzinfo=timezone.utc),
+                dt(2001, 6, 1, tzinfo=timezone.utc),
+            ): [9, 10],
+            (
+                dt(2001, 6, 1, tzinfo=timezone.utc),
+                dt(2001, 7, 1, tzinfo=timezone.utc),
+            ): [11, 12],
+            (
+                dt(2001, 7, 1, tzinfo=timezone.utc),
+                dt(2001, 8, 1, tzinfo=timezone.utc),
+            ): [13, 14],
+            (
+                dt(2001, 8, 1, tzinfo=timezone.utc),
+                dt(2001, 9, 1, tzinfo=timezone.utc),
+            ): [15, 16],
+            (
+                dt(2001, 9, 1, tzinfo=timezone.utc),
+                dt(2001, 10, 1, tzinfo=timezone.utc),
+            ): [17, 18],
+            (
+                dt(2001, 10, 1, tzinfo=timezone.utc),
+                dt(2001, 11, 1, tzinfo=timezone.utc),
+            ): [19, 20],
+            (
+                dt(2001, 11, 1, tzinfo=timezone.utc),
+                dt(2001, 12, 1, tzinfo=timezone.utc),
+            ): [21, 22],
         }