Blocks until a given time (Python)

til.py

"""
blocks until a specific time, 
useful for planning to run a script at a specific time

usage: 

python til.py 13:00 tomorrow && python script.py
"""
import dateparser
from datetime import datetime, timedelta
import time
import argparse

parser = argparse.ArgumentParser(description='Block until run time')
parser.add_argument('time', type=str, nargs='+')
args = parser.parse_args()
run_time = ' '.join(args.time)
tgt = dateparser.parse(run_time)
print('will run at:', tgt)

while True:
    now = dateparser.parse('now')
    if tgt < now: break
    print('wait for:', tgt - now)
    time.sleep(10)