The intention is that you customise the timezones to suit your needs and then save the corresponding URL as a bookmark or similar.
Customise timezones: Add ?tz= to the URL with comma-separated timezone
names.
Custom labels: Add :CustomName after any timezone to override the
default location name.
Examples:
?tz=Europe/London,America/New_York,America/Los_Angeles?tz=Europe/London,America/Chicago,America/Los_Angeles:San Francisco?tz=Europe/London:UK,America/New_York:NYC,America/Los_Angeles:SFCommon timezones: