#!/usr/bin/env python

import argparse

import dateparser

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Convert date from human format")
    parser.add_argument(
        "when", type=dateparser.parse, help="date specification, e.g. 'yesterday'"
    )
    args = parser.parse_args()
    print(args.when.strftime("%Y_%m_%d"))