diff --git a/satip/filenames.py b/satip/filenames.py
index cf7341aa..c8b1bda1 100644
--- a/satip/filenames.py
+++ b/satip/filenames.py
@@ -13,7 +13,6 @@ def get_datetime_from_filename(filename: str, strip_hrv: bool = False) -> pd.Tim
     """
 
     filename = filename.replace("iodc_", "")
-    filename = filename.replace("15_", "")
 
     if strip_hrv:
         filename = filename.replace("hrv_", "")
diff --git a/tests/unit_test/test_filenames.py b/tests/unit_test/test_filenames.py
index 5af00fd7..b08cfc2e 100644
--- a/tests/unit_test/test_filenames.py
+++ b/tests/unit_test/test_filenames.py
@@ -14,10 +14,10 @@ def test_get_time_from_filename():
     assert datetime == "hrv_202408261815"
 
     datetime = get_datetime_from_filename("folder/15_hrv_202408261815.zarr.zip")
-    assert datetime == "hrv_202408261815"
+    assert datetime == "15_hrv_202408261815"
 
     datetime = get_datetime_from_filename("folder/hrv_202408261815.zarr.zip", strip_hrv=True)
     assert datetime == pd.Timestamp("2024-08-26 18:15", tz="UTC")
 
     datetime = get_datetime_from_filename("folder/15_hrv_202408261815.zarr.zip", strip_hrv=True)
-    assert datetime == pd.Timestamp("2024-08-26 18:15", tz="UTC")
+    assert datetime == "15_202408261815"