Perth is typically 8 hours ahead of London. When it's 5:00 PM in Perth, it's 9:00 AM in London. Perth does not observe daylight saving time, but London does.
During UK summer time (late March to late October), the difference is 7 hours. During UK winter time (late October to late March), the difference increases to 8 hours.
Optimal meeting window: 4:00 PM - 6:00 PM Perth time (8:00 AM - 10:00 AM London, or 9:00 AM - 11:00 AM in winter). Late afternoon Perth catches morning London.
Perth has strong historical ties to the UK, and many British expats call Western Australia home. Mining companies with UK headquarters often maintain operations in Perth, Australia's resource capital.