make EDF writer handle anonymized meas_date

Author: drammock

mne_bids/write.py

@@ -1338,7 +1338,7 @@ def _write_raw_brainvision(raw, bids_fname, events, overwrite):
     )
 
 
-def _write_raw_edf(raw, bids_fname, overwrite):
+def _write_raw_edf_bdf(raw, bids_fname, overwrite):
     """Store data as EDF.
 
     Parameters
@@ -1350,8 +1350,24 @@ def _write_raw_edf(raw, bids_fname, overwrite):
     overwrite : bool
         Whether to overwrite an existing file or not.
     """
-    assert str(bids_fname).endswith(".edf")
-    raw.export(bids_fname, overwrite=overwrite)
+    ext = bids_fname.suffix[1:].upper()
+    assert ext in ("EDF", "BDF")
+    if raw.info["meas_date"] is not None and raw.info["meas_date"].year < 1985:
+        warn(
+            f"Attempting to write a {ext} file with a meas_date of "
+            f"{raw.info['meas_date']}. This is not supported; {ext} limits `startdate` "
+            "to dates after 1985-01-01. Setting `startdate` to 1985-01-01 00:00:00 in "
+            f"the {ext} file; the original anonymized date will be written to scans.tsv"
+        )
+    # make a copy, so that anonymized meas_date is unchanged in orig raw,
+    # and thus scans.tsv ends up with the properly anonymized meas_date
+    raw_anon = raw.copy()
+    raw_anon.set_meas_date(
+        raw.info["meas_date"].replace(
+            year=1985, month=1, day=1, hour=0, minute=0, second=0, microsecond=0
+        )
+    )
+    raw_anon.export(bids_fname, overwrite=overwrite)
 
 
 def _write_raw_eeglab(raw, bids_fname, overwrite):
@@ -2361,7 +2377,7 @@ def write_raw_bids(
             )
         elif bids_path.datatype in ["eeg", "ieeg"] and format == "EDF":
             warn("Converting data files to EDF format")
-            _write_raw_edf(raw, bids_path.fpath, overwrite=overwrite)
+            _write_raw_edf_bdf(raw, bids_path.fpath, overwrite=overwrite)
         elif bids_path.datatype in ["eeg", "ieeg"] and format == "EEGLAB":
             warn("Converting data files to EEGLAB format")
             _write_raw_eeglab(raw, bids_path.fpath, overwrite=overwrite)