Timezone.io is described as 'Modern global teams have awesome people spread across multiple timezones. Lots of teams have digital nomads changing locations faster than we can keep up with. Often it gets tricky to remember what time it is where your teammates are. Enter Timezone.io' and is an website in the Office & Productivity category. There are five alternatives to Timezone.io, not only websites but also apps for iPhone, iPad and Slack. The best alternative is Spacetime, which is free. Other great sites and apps similar to Timezone.io are Every Time Zone (Free), Dilims (Paid), Channel Time (Free, Open Source) and Time&Time (Paid).
Dilims lets you display different time slots in different time zones to quickly find other peoples local times. Add your co-workers working hours and quickly find overlapping times. - Add multiple time slots for each time zone.
Use /time to convert times Don't ask if that the time is in your time zone or your teammate's time zone. Start a message with /time and Channel Time will automatically parse your message to convert the time for everybody in the room.