import dateutil.parser
from datetime import datetime, timedelta, timezone
epoch = datetime(1970, 1, 1, tzinfo=timezone.utc)
sDate = "2018-02-27T14:03:15Z"
dt = dateutil.parser.parse(sDate)
ts = (dt - epoch) // timedelta(seconds=1)
source:
https://stackoverflow.com/questions/8777753/converting-datetime-date-to-utc-timestamp-in-python