gopro-cut duration syntax

[DougEdwards47]

What is the exact syntax for specifying the duration (or start or end). I have tried:
--duration 00:10:10.000000
--duration (00:10:10.000000)
--duration (00:10:10.000000)
--duration "00:10:10.000000"
A typical error message is:
Traceback (most recent call last):
File "/usr/local/bin/venv/bin/gopro-cut.py", line 33, in
from_seconds = as_seconds(args.start)
^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/bin/venv/bin/gopro-cut.py", line 13, in as_seconds
parsed_time = parse_time(timey)
^^^^^^^^^^^^^^^^^
File "/usr/local/bin/venv/lib/python3.12/site-packages/gopro_overlay/parsing.py", line 7, in parse_time
return datetime.strptime(s, f)
^^^^^^^^^^^^^^^^^^^^^^^
TypeError: strptime() argument 1 must be str, not None

[time4tea]

You should be able to pass in any of the following:
10 - 10 seconds
10.2 - 10.2 seconds
1:10 - 1 min 10 seconds
1:10.2 - 1 min 10.2 seconds
1:1:3 - 1 hour 1 minutes 3 seconds
1:1:3.2 - 1 hour 1 minutes 3.2 seconds

it seems to be complaining about the value for --start though, not duration?