There is Swatch Internet Time (.beat), which was invented to:

… simplify the way people in different time zones communicate about time, mostly by eliminating time zones altogether. It also does away with the division of the day into 12 or 24 parts (hours), then 60 parts (minutes), then 60 parts (seconds), then 1000 parts (milliseconds). Furthermore, there is no confusion between the AM/PM system and 24-hour time.

For example:

Internet time clock