Convert date to millisecond timestamp

convert-date-to-milliseconds.py

# requires dateparser package
import dateparser
import pytz
from datetime import datetime


def date_to_milliseconds(date_str):
    """Convert UTC date to milliseconds

    If using offset strings add "UTC" to date string e.g. "now UTC", "11 hours ago UTC"

    See dateparse docs for formats http://dateparser.readthedocs.io/en/latest/

    :param date_str: date in readable format, i.e. "January 01, 2018", "11 hours ago UTC", "now UTC"
    :type date_str: str
    """
    # get epoch value in UTC
    epoch = datetime.utcfromtimestamp(0).replace(tzinfo=pytz.utc)
    # parse our date string
    d = dateparser.parse(date_str)
    # if the date is not timezone aware apply UTC timezone
    if d.tzinfo is None or d.tzinfo.utcoffset(d) is None:
        d = d.replace(tzinfo=pytz.utc)

    # return the difference in time
    return int((d - epoch).total_seconds() * 1000.0)