Timezone.io - Keep track where and when your team is.
Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.
TimeZoneNinja - Scheduling meetings around the world just got easy
BusyCal - powerful calendar app for macOS
Startup Timelines - How the frontpages of famous startups changed over time
Google Calendar - Spend less time managing your day & more time enjoying it