def tz_to_str(tz_seconds: int) -> str:
    """convert timezone offset in seconds to string in form +00:00 (as offset from GMT)"""
    sign = "+" if tz_seconds >= 0 else "-"
    tz_seconds = abs(tz_seconds)
    # get min and seconds first
    mm, _ = divmod(tz_seconds, 60)
    # Get hours
    hh, mm = divmod(mm, 60)
    return f"{sign}{hh:02}{mm:02}"