diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 3839e5fd9..a321f1be1 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ '3.8', '3.9', '3.10', '3.11']
+        python-version: [ '3.8', '3.9', '3.10', '3.11', '3.12']
     name: Tests on ${{ matrix.python-version }}
     steps:
       - name: Setup python
diff --git a/docs/changelog/v3.2.x.rst b/docs/changelog/v3.2.x.rst
index 56380de5b..fb89f2b92 100644
--- a/docs/changelog/v3.2.x.rst
+++ b/docs/changelog/v3.2.x.rst
@@ -10,6 +10,12 @@ Bug Fixes
 - Fix incorrect lap number (zero instead of one) for generated laps that are
   added when a driver crashes on the very first lap.
 
+- Fix broken schedule backend 'f1timing' (failed to load 2023 season schedule
+  after Qatar GP due to unexpected data)
+
+- Fix: failing lap accuracy check for one driver caused laps of all drivers to
+  be marked as inaccurate (#464)
+
 
 New Features
 ^^^^^^^^^^^^
diff --git a/fastf1/core.py b/fastf1/core.py
index 4d3590747..faa6e37ee 100644
--- a/fastf1/core.py
+++ b/fastf1/core.py
@@ -1421,6 +1421,11 @@ def _load_laps_data(self, livedata=None):
             mask = pd.isna(result['LapStartTime']) & (~pd.isna(result['PitOutTime']))
             result.loc[mask, 'LapStartTime'] = result.loc[mask, 'PitOutTime']
 
+            # remove first lap pitout time if it is before session_start_time
+            mask = (result["PitOutTime"] < self.session_start_time) & \
+                   (result["NumberOfLaps"] == 1)
+            result.loc[mask, 'PitOutTime'] = pd.NaT
+
             # create total laps counter for each tyre used
             for npit in result['Stint'].unique():
                 sel = result['Stint'] == npit
@@ -1867,6 +1872,7 @@ def _check_lap_accuracy(self):
             prev_lap = None
             integrity_errors = 0
             for _, lap in self.laps[self.laps['DriverNumber'] == drv].iterrows():
+                lap_integrity_ok = True
                 # require existence, non-existence and specific values for some variables
                 check_1 = (pd.isnull(lap['PitInTime'])
                            & pd.isnull(lap['PitOutTime'])
@@ -1884,7 +1890,7 @@ def _check_lap_accuracy(self):
                                           lap['LapTime'].total_seconds(),
                                           atol=0.003, rtol=0, equal_nan=False)
                     if not check_2:
-                        integrity_errors += 1
+                        lap_integrity_ok = False
                 else:
                     check_2 = False  # data not available means fail
 
@@ -1894,16 +1900,44 @@ def _check_lap_accuracy(self):
                 else:
                     check_3 = True  # no previous lap, no SC error
 
-                result = check_1 and check_2 and check_3
+                pre_check_4 = (((not pd.isnull(lap['Time']))
+                               & (not pd.isnull(lap['LapTime'])))
+                               and (prev_lap is not None)
+                               and (not pd.isnull(prev_lap['Time'])))
+
+                if pre_check_4:  # needed condition for check_4
+                    time_diff = np.sum((lap['Time'],
+                                        -1 * prev_lap['Time'])).total_seconds()
+                    lap_time = lap['LapTime'].total_seconds()
+                    # If the difference between the two times is within a
+                    # certain tolerance, the lap time data is considered
+                    # to be valid.
+                    check_4 = np.allclose(time_diff, lap_time,
+                                          atol=0.003, rtol=0, equal_nan=False)
+
+                    if not check_4:
+                        lap_integrity_ok = False
+
+                else:
+                    check_4 = True
+
+                if not lap_integrity_ok:
+                    integrity_errors += 1
+
+                result = check_1 and check_2 and check_3 and check_4
                 is_accurate.append(result)
                 prev_lap = lap
 
             if len(is_accurate) > 0:
-                self._laps.loc[self.laps['DriverNumber'] == drv, 'IsAccurate'] = is_accurate
+                self._laps.loc[
+                    self.laps['DriverNumber'] == drv, 'IsAccurate'
+                ] = is_accurate
             else:
-                _logger.warning("Failed to perform lap accuracy check - all "
-                                "laps marked as inaccurate.")
-                self.laps['IsAccurate'] = False  # default should be inaccurate
+                _logger.warning(f"Failed to perform lap accuracy check - all "
+                                f"laps marked as inaccurate (driver {drv})")
+                self._laps.loc[
+                    self.laps['DriverNumber'] == drv, 'IsAccurate'
+                ] = False  # default should be inaccurate
 
             # necessary to explicitly cast to bool
             self._laps[['IsAccurate']] \
diff --git a/fastf1/events.py b/fastf1/events.py
index c378825eb..042bb7962 100644
--- a/fastf1/events.py
+++ b/fastf1/events.py
@@ -110,7 +110,7 @@
 identifier to differentiate between the various sessions of one event.
 This identifier can currently be one of the following:
 
-    - session name abbreviation: ``'FP1', 'FP2', 'FP3', 'Q', 'S', 'SS', R'``
+    - session name abbreviation: ``'FP1', 'FP2', 'FP3', 'Q', 'S', 'SS', 'R'``
     - full session name: ``'Practice 1', 'Practice 2',
       'Practice 3', 'Sprint', 'Sprint Shootout', 'Qualifying', 'Race'``;
       provided names will be normalized, so that the name is
@@ -607,15 +607,21 @@ def _get_schedule_from_f1_timing(year):
         data['EventName'].append(event['Name'])
         data['OfficialEventName'].append(event['OfficialName'])
 
-        n_events = min(len(event['Sessions']), 5)
+        # select only valid sessions
+        sessions = list()
+        for ses in event['Sessions']:
+            if (ses.get('Key') != -1) and ses.get('Name'):
+                sessions.append(ses)
+
+        n_events = min(len(sessions), 5)
         # number of events, usually 3 for testing, 5 for race weekends
         # in special cases there are additional unrelated events
 
-        if (n_events >= 4) and ('Sprint' in event['Sessions'][3]['Name']):
-            if event['Sessions'][3]['Name'] == 'Sprint Qualifying':
+        if (n_events >= 4) and ('Sprint' in sessions[3]['Name']):
+            if sessions[3]['Name'] == 'Sprint Qualifying':
                 # fix for 2021 where Sprint was called Sprint Qualifying
-                event['Sessions'][3]['Name'] = 'Sprint'
-            if event['Sessions'][2]['Name'] == 'Sprint Shootout':
+                sessions[3]['Name'] = 'Sprint'
+            if sessions[2]['Name'] == 'Sprint Shootout':
                 data['EventFormat'].append('sprint_shootout')
             else:
                 data['EventFormat'].append('sprint')
@@ -632,7 +638,7 @@ def _get_schedule_from_f1_timing(year):
         for i in range(0, 5):
             # parse the up to five sessions for each event
             try:
-                session = event['Sessions'][i]
+                session = sessions[i]
             except IndexError:
                 data[f'Session{i+1}'].append(None)
                 data[f'Session{i+1}Date'].append(None)
@@ -730,6 +736,9 @@ def _get_schedule_from_ergast(year) -> "EventSchedule":
 class EventSchedule(pd.DataFrame):
     """This class implements a per-season event schedule.
 
+    For detailed information about the information that is available for each
+    event, see `Event Schedule Data`_.
+
     This class is usually not instantiated directly. You should use
     :func:`fastf1.get_event_schedule` to get an event schedule for a specific
     season.
@@ -928,6 +937,9 @@ class Event(pd.Series):
     Each event consists of one or multiple sessions, depending on the type
     of event and depending on the event format.
 
+    For detailed information about the information that is available for each
+    event, see `Event Schedule Data`_.
+
     This class is usually not instantiated directly. You should use
     :func:`fastf1.get_event` or similar to get a specific event.
 
diff --git a/fastf1/tests/test_core.py b/fastf1/tests/test_core.py
index 561e23c12..5294577ad 100644
--- a/fastf1/tests/test_core.py
+++ b/fastf1/tests/test_core.py
@@ -39,6 +39,23 @@ def test_lap_data_loading_position_calculation():
         assert (delta == 0).all()  # assert that the delta is zero for all laps
 
 
+@pytest.mark.f1telapi
+def test_first_lap_pitout_times():
+    sprint_session = fastf1.get_session(2023, 4, "Sprint")
+    sprint_session.load(telemetry=False, weather=False, messages=False)
+    sprint_laps = sprint_session.laps
+    sprint_mask = (sprint_laps["LapNumber"] == 1) & \
+                  (~sprint_laps["PitOutTime"].isna())
+    assert sprint_laps[sprint_mask]["Driver"].tolist() == ["OCO"]
+
+    race_session = fastf1.get_session(2023, 5, "R")
+    race_session.load(telemetry=False, weather=False, messages=False)
+    race_laps = race_session.laps
+    race_mask = (race_laps["LapNumber"] == 1) & \
+                (~race_laps["PitOutTime"].isna())
+    assert race_laps[race_mask]["Driver"].tolist() == []
+
+
 def test_laps_constructor_metadata_propagation(reference_laps_data):
     session, laps = reference_laps_data
 
diff --git a/pytest.ini b/pytest.ini
index d9f6b8845..5c25857b3 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -23,3 +23,10 @@ filterwarnings =
   # external, verified as not relevant
   # (10/2022)
   ignore:.*df.iloc.*will attempt to set the values inplace.*:FutureWarning
+  # external, datetime module deprecation
+  # (11/2023)
+  ignore:.*datetime\.datetime.utcnow\(\) is deprecated.*:DeprecationWarning
+  ignore:.*datetime\.datetime.utcfromtimestamp\(\) is deprecated.*:DeprecationWarning
+  # external, attribute removal planned for Python 3.14
+  # (11/2023)
+  ignore:.*Attribute s is deprecated and will be removed in Python 3.14.*:DeprecationWarning