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.

Open source

If you'd rather host this yourself or you just want to peek under the hook, go ahead and check out the source code for Channel Time.

Here are the permissions that Channel Time needs and why:

Confirm your identity: get the Slack ID for the user adding this app
Add commands: to add the /time command
Access information about your public channels: to be able to match channel members with their time zone
Send messages as Channel Time: to post the modified message with time zone information
Access your team's profile information: to find each team member's time zone