text: import datetime
  import re
  
  
  def parse_timezone(s: str):
      regexp = re.compile(r"^UTC(([+-][0-2][0-9]):([0-5][0-9]))?$")
      match = regexp.match(s)
      if not match:
          raise ValueError(
              f"Time zone {s} must be either UTC " f"or in format UTC[+-]hh:mm"
          )
      if match.group(1):
          hours = int(match.group(2))
          minutes = int(match.group(3))
          return datetime.timezone(
              datetime.timedelta(
                  hours=hours, minutes=minutes if hours >= 0 else -minutes
              )
          )
      else:
          return datetime.timezone.utc
  
  
  __all__ = [
      "parse_timezone",
  ]
  