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.
Permissions
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
