Set it up in Slack or give it a try below:

/tz
↵  
  • Chicago, US: 1:53 am CDT, Thu Oct 1st
  • Chicago is 1 hour behind you
  • Los Angeles, US: 11:53 pm PDT, Wed Sep 30th
  • Los Angeles is 3 hours behind you
  • Paris, FR: 8:53 am CEST, Thu Oct 1st
  • Paris is 6 hours ahead of you
  • Mumbai, IN: 12:23 pm IST, Thu Oct 1st
  • Mumbai is 9.5 hours ahead of you
  • Chicago is 2 hours ahead of Los Angeles
  • Chicago is 7 hours behind Paris
  • Chicago is 10.5 hours behind Mumbai

Examples: