# ~ If the program is called with '-h' option, it fails due to %Y in the
# ~ help message of the --from argument, producing this error:
# ~ File "/usr/lib/python3.8/argparse.py", line 633, in _expand_help
    # ~ return self._get_help_string(action) % params
# ~ ValueError: unsupported format character 'Y' (0x59) at index 18

import argparse

parser = argparse.ArgumentParser(
	description = 'Plots the standby data.'
)
parser.add_argument(
	'--from',
	metavar = 'when', 
	help = 	'A date in format %Y-%m-%d',
	dest = f'From',
	type = str,
	required = True,
)
args = parser.parse_args()

print(args.From)