diff --git a/app/scodoc/sco_excel.py b/app/scodoc/sco_excel.py
index 32cf27c0..c9551b69 100644
--- a/app/scodoc/sco_excel.py
+++ b/app/scodoc/sco_excel.py
@@ -79,52 +79,11 @@ def send_excel_file(request, data, filename, mime=scu.XLSX_MIMETYPE):
 # font, border, number_format, fill, ..  (cf https://openpyxl.readthedocs.io/en/stable/styles.html#working-with-styles)
 
 
-#  (stolen from xlrd)
-# Convert an Excel number (presumed to represent a date, a datetime or a time) into
-# a Python datetime.datetime
-# @param xldate The Excel number
-# @param datemode 0: 1900-based, 1: 1904-based.
-# @return a datetime.datetime object, to the nearest_second.
-# <br>Special case: if 0.0 <= xldate < 1.0, it is assumed to represent a time;
-# a datetime.time object will be returned.
-# <br>Note: 1904-01-01 is not regarded as a valid date in the datemode 1 system; its "serial number"
-# is zero.
-#
-# _XLDAYS_TOO_LARGE = (2958466, 2958466 - 1462)  # This is equivalent to 10000-01-01
-#
-
-
 def xldate_as_datetime(xldate, datemode=0):
+    """Conversion d'une date Excel en date
+    Peut lever une ValueError
+    """
     return openpyxl.utils.datetime.from_ISO8601(xldate)
-    # if datemode not in (0, 1):
-    #     raise ValueError("invalid mode %s" % datemode)
-    # if xldate == 0.00:
-    #     return datetime.time(0, 0, 0)
-    # if xldate < 0.00:
-    #     raise ValueError("invalid date code %s" % xldate)
-    # xldays = int(xldate)
-    # frac = xldate - xldays
-    # seconds = int(round(frac * 86400.0))
-    # assert 0 <= seconds <= 86400
-    # if seconds == 86400:
-    #     seconds = 0
-    #     xldays += 1
-    # if xldays >= _XLDAYS_TOO_LARGE[datemode]:
-    #     raise ValueError("date too large %s" % xldate)
-    #
-    # if xldays == 0:
-    #     # second = seconds % 60; minutes = seconds // 60
-    #     minutes, second = divmod(seconds, 60)
-    #     # minute = minutes % 60; hour    = minutes // 60
-    #     hour, minute = divmod(minutes, 60)
-    #     return datetime.time(hour, minute, second)
-    #
-    # if xldays < 61 and datemode == 0:
-    #     raise ValueError("ambiguous date %s" % xldate)
-    #
-    # return datetime.datetime.fromordinal(
-    #     xldays + 693594 + 1462 * datemode
-    # ) + datetime.timedelta(seconds=seconds)
 
 
 class ScoExcelBook:
diff --git a/app/scodoc/sco_import_etuds.py b/app/scodoc/sco_import_etuds.py
index 5e5016bc..b9b8b5de 100644
--- a/app/scodoc/sco_import_etuds.py
+++ b/app/scodoc/sco_import_etuds.py
@@ -378,8 +378,12 @@ def scolars_import_excel_file(
                 # Excel date conversion:
                 if titleslist[i].lower() == "date_naissance":
                     if val:
-                        # if re.match(r"^[0-9]*\.?[0-9]*$", str(val)):
-                        val = sco_excel.xldate_as_datetime(val)
+                        try:
+                            val = sco_excel.xldate_as_datetime(val)
+                        except ValueError:
+                            raise ScoValueError(
+                                f"date invalide ({val}) sur ligne {linenum}, colonne {titleslist[i]}"
+                            )
                 # INE
                 if (
                     titleslist[i].lower() == "code_ine"