TypeError: 'NoneType' object is not subscriptable

[unclehowell]

Traceback (most recent call last):
File "/home/user/Downloads/mbox-to-csv/mbox_parser.py", line 115, in
date = get_date(email["date"], os.getenv("DATE_FORMAT"))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/unclehowell/Downloads/mbox-to-csv/mbox_parser.py", line 23, in get_date
utc_seconds_since_epoch = mktime_tz(time_tuple)
^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.11/email/_parseaddr.py", line 193, in mktime_tz
if data[9] is None:
~~~~^^^
TypeError: 'NoneType' object is not subscriptable