presto-spi/src/main/java/io/prestosql/spi/type/TimeZoneKey.java/TimeZoneKey/zoneIdForOffset
class TimeZoneKey:    private static String zoneIdForOffset(long offset)
    {
        return format("%s%02d:%02d", offset < 0 ? "-" : "+", abs(offset / 60), abs(offset % 60));
    }