diff --git a/src/osekit/core/audio_dataset.py b/src/osekit/core/audio_dataset.py
index 388d173b..32fe8c72 100644
--- a/src/osekit/core/audio_dataset.py
+++ b/src/osekit/core/audio_dataset.py
@@ -176,7 +176,7 @@ def _data_from_dict(cls, dictionary: dict) -> list[AudioData]:
     def from_folder(  # noqa: PLR0913
         cls,
         folder: Path,
-        strptime_format: str | None,
+        strptime_format: str | list[str] | None,
         begin: Timestamp | None = None,
         end: Timestamp | None = None,
         timezone: str | pytz.timezone | None = None,
@@ -195,7 +195,7 @@ def from_folder(  # noqa: PLR0913
         ----------
         folder: Path
             The folder containing the audio files.
-        strptime_format: str | None
+        strptime_format: str | list[str] | None
             The strptime format used in the filenames.
             It should use valid strftime codes (https://strftime.org/).
             If ``None``, the first audio file of the folder will start
diff --git a/src/osekit/core/audio_file.py b/src/osekit/core/audio_file.py
index 619b3361..0c133f93 100644
--- a/src/osekit/core/audio_file.py
+++ b/src/osekit/core/audio_file.py
@@ -45,7 +45,7 @@ def __init__(
             If it is not provided, ``strptime_format`` is mandatory.
             If both ``begin`` and ``strptime_format`` are provided,
             ``begin`` will overrule the timestamp embedded in the filename.
-        strptime_format: str | None
+        strptime_format: str | list[str] | None
             The strptime format used in the text.
             It should use valid strftime codes (https://strftime.org/).
             Example: ``'%y%m%d_%H:%M:%S'``.
diff --git a/src/osekit/core/base_dataset.py b/src/osekit/core/base_dataset.py
index 33a749d4..3ffeebfb 100644
--- a/src/osekit/core/base_dataset.py
+++ b/src/osekit/core/base_dataset.py
@@ -511,7 +511,7 @@ def _get_data_from_files_timedelta_file(
     def from_folder(  # noqa: PLR0913
         cls: type[Self],
         folder: Path,
-        strptime_format: str | None,
+        strptime_format: str | list[str] | None,
         begin: Timestamp | None = None,
         end: Timestamp | None = None,
         timezone: str | pytz.timezone | None = None,
@@ -528,7 +528,7 @@ def from_folder(  # noqa: PLR0913
         ----------
         folder: Path
             The folder containing the files.
-        strptime_format: str | None
+        strptime_format: str | list[str] | None
             The strptime format used in the filenames.
             It should use valid strftime codes (https://strftime.org/).
             If None, the first audio file of the folder will start
@@ -619,7 +619,7 @@ def from_folder(  # noqa: PLR0913
     def _parse_file(
         cls: type[Self],
         file: Path,
-        strptime_format: str,
+        strptime_format: str | list[str] | None,
         timezone: str | pytz.timezone | None,
         begin_timestamp: Timestamp,
         valid_files: list[TFile],
diff --git a/src/osekit/core/base_file.py b/src/osekit/core/base_file.py
index 08f32402..f3df8fc4 100644
--- a/src/osekit/core/base_file.py
+++ b/src/osekit/core/base_file.py
@@ -62,7 +62,7 @@ def __init__(
             ``begin`` will overrule the timestamp embedded in the filename.
         end: pandas.Timestamp | None
             (Optional) timestamp after the last data point in the file.
-        strptime_format: str | None
+        strptime_format: str | list[str] | None
             The strptime format used in the text.
             It should use valid strftime codes (https://strftime.org/).
             Example: ``'%y%m%d_%H:%M:%S'``.
diff --git a/src/osekit/core/spectro_dataset.py b/src/osekit/core/spectro_dataset.py
index e962e6d3..71415bb5 100644
--- a/src/osekit/core/spectro_dataset.py
+++ b/src/osekit/core/spectro_dataset.py
@@ -527,7 +527,7 @@ def from_dict(cls, dictionary: dict) -> SpectroDataset:
     def from_folder(  # noqa: PLR0913
         cls,
         folder: Path,
-        strptime_format: str,
+        strptime_format: str | list[str] | None,
         begin: Timestamp | None = None,
         end: Timestamp | None = None,
         timezone: str | pytz.timezone | None = None,
@@ -543,7 +543,7 @@ def from_folder(  # noqa: PLR0913
         ----------
         folder: Path
             The folder containing the spectro files.
-        strptime_format: str
+        strptime_format: str | list[str] | None
             The strptime format of the timestamps in the spectro file names.
         begin: Timestamp | None
             The begin of the spectro dataset.
diff --git a/src/osekit/core/spectro_file.py b/src/osekit/core/spectro_file.py
index 141de35f..041e6db8 100644
--- a/src/osekit/core/spectro_file.py
+++ b/src/osekit/core/spectro_file.py
@@ -51,7 +51,7 @@ def __init__(
             If it is not provided, ``strptime_format`` is mandatory.
             If both ``begin`` and ``strptime_format`` are provided,
             ``begin`` will overrule the timestamp embedded in the filename.
-        strptime_format: str | None
+        strptime_format: str | list[str] | None
             The strptime format used in the text.
             It should use valid strftime codes (https://strftime.org/).
             Example: ``'%y%m%d_%H:%M:%S'``.
diff --git a/src/osekit/public/project.py b/src/osekit/public/project.py
index 23288dc2..a9235ee4 100644
--- a/src/osekit/public/project.py
+++ b/src/osekit/public/project.py
@@ -53,7 +53,7 @@ class Project:
     def __init__(  # noqa: PLR0913
         self,
         folder: Path,
-        strptime_format: str | None,
+        strptime_format: str | list[str] | None,
         gps_coordinates: str | list | tuple = (0, 0),
         depth: float = 0.0,
         timezone: str | None = None,
@@ -68,7 +68,7 @@ def __init__(  # noqa: PLR0913
         ----------
         folder: Path
             Path to the folder containing the original audio files.
-        strptime_format: str | None
+        strptime_format: str | list[str] | None
             The strptime format used in the filenames.
             It should use valid strftime codes (https://strftime.org/).
             If ``None``, the first audio file of the folder will start
diff --git a/tests/test_audio.py b/tests/test_audio.py
index 3f9c6122..c15422b9 100644
--- a/tests/test_audio.py
+++ b/tests/test_audio.py
@@ -965,6 +965,23 @@ def test_normalize_audio_data(
             generate_sample_audio(1, 48_000),
             id="one_entire_file",
         ),
+        pytest.param(
+            {
+                "duration": 1,
+                "sample_rate": 48_000,
+                "nb_files": 1,
+                "date_begin": pd.Timestamp("2024-01-01 12:00:00"),
+                "series_type": "increase",
+            },
+            None,
+            None,
+            "timedelta_total",
+            ["%y%H%M__%s", TIMESTAMP_FORMAT_EXPORTED_FILES_UNLOCALIZED, "%Y%H%m__%f"],
+            None,
+            None,
+            generate_sample_audio(1, 48_000),
+            id="first_valid_strptime_format_is_used",
+        ),
         pytest.param(
             {
                 "duration": 1,
@@ -1149,7 +1166,7 @@ def test_audio_dataset_from_folder(
     begin: pd.Timestamp | None,
     end: pd.Timestamp | None,
     mode: Literal["files", "timedelta_total", "timedelta_file"],
-    strptime_format: str,
+    strptime_format: str | list[str],
     first_file_begin: Timestamp | None,
     duration: pd.Timedelta | None,
     expected_audio_data: list[np.ndarray],
diff --git a/tests/test_core_api_base.py b/tests/test_core_api_base.py
index 8a3ba3c4..c437afc9 100644
--- a/tests/test_core_api_base.py
+++ b/tests/test_core_api_base.py
@@ -456,6 +456,28 @@ def test_base_dataset_from_files_overlap_errors(overlap: float, mode: str) -> No
             ],
             id="one_file_default",
         ),
+        pytest.param(
+            ["%Y%m%d%H%M%S%f", "%y%m%d%H%M%S", "%y%m%d%H%M%S%z"],
+            None,
+            None,
+            None,
+            "files",
+            0.0,
+            None,
+            None,
+            None,
+            [Path(r"231201000000")],
+            [
+                (
+                    Event(
+                        begin=Timestamp("2023-12-01 00:00:00"),
+                        end=Timestamp("2023-12-01 00:00:01"),
+                    ),
+                    [Path(r"231201000000")],
+                ),
+            ],
+            id="first_matching_strptime_format_is_used",
+        ),
         pytest.param(
             None,
             None,
@@ -735,7 +757,7 @@ def test_base_dataset_from_files_overlap_errors(overlap: float, mode: str) -> No
 )
 def test_base_dataset_from_folder(
     monkeypatch: pytest.monkeypatch,
-    strptime_format: str | None,
+    strptime_format: str | list[str] | None,
     begin: Timestamp | None,
     end: Timestamp | None,
     timezone: str | None,
diff --git a/tests/test_files.py b/tests/test_files.py
index d3bbe0eb..6f78810f 100644
--- a/tests/test_files.py
+++ b/tests/test_files.py
@@ -73,11 +73,18 @@
             Timestamp("2004-05-03 19:12:12", tz="UTC+01:00"),
             id="aware_strptime_converted_to_provided_utc_offset",
         ),
+        pytest.param(
+            "040503121212_-0600.foo",
+            ["%y%m%d%H%M%S_%f", "%y%m%d%H%M%S_%z", "%y%m%d%H%M%S"],
+            "+0100",
+            Timestamp("2004-05-03 19:12:12", tz="UTC+01:00"),
+            id="first_matching_format_is_used",
+        ),
     ],
 )
 def test_file_localization(
     file_name: str,
-    strptime_format: str,
+    strptime_format: str | list[str],
     timezone: str | pytz.timezone | None,
     expected_begin: Timestamp,
 ) -> None:
@@ -163,7 +170,7 @@ def test_file_localization(
 def test_dataset_localization(
     tmp_path: Path,
     file_names: list[str],
-    strptime_format: str,
+    strptime_format: str | list[str],
     timezone: str | pytz.timezone | None,
     expected_begins: list[Timestamp],
 ) -> None: