docs: def to_epoch(t):
      """Take a datetime, either as a string or a datetime.datetime object,
      and return the corresponding epoch"""
      if isinstance(t, str):
          if '+' not in t:
              t = t + '+00:00'
          t = parser.parse(t)
      elif t.tzinfo is None or t.tzinfo.utcoffset(t) is None:
          t = t.replace(tzinfo=pytz.timezone('utc'))
  
      t0 = datetime.datetime(1970, 1, 1, 0, 0, 0, 0, pytz.timezone('utc'))
      delta = t - t0
      return int(delta.total_seconds())