There are 2 options of patterns you can download, the major difference is the clock faces:

1. Full clock face with 24 time zones and cities.

2. Full clock face with 24 time zones with no cities.

Of course you can customize the clock face with only the time zones and cities you care about. An ai file is here so you can use adobe illustrator or Inkscape (free) to edit it. You can also mark the slots where you have family and friends.

Make sure to print it out with 100% scale.