Which Countries Use 24 Hour Time?

Most Countries Use 24-Hour Time

The 24-hour clock is the dominant global timekeeping standard. The vast majority of countries worldwide use 24-hour time in government communication, transportation systems, healthcare, aviation, and military operations.

This format is standard across Europe, Asia, Africa, Latin America, and most of the Middle East. Countries including Germany, France, Japan, China, Brazil, Russia, and Saudi Arabia use 24-hour time as their primary system.

Several territories and dependencies—such as Hong Kong, Puerto Rico, and Greenland—also use 24-hour time but are not sovereign countries.

12-Hour Time Is Concentrated in English-Influenced Countries

The 12-hour clock is primarily used in a smaller group of countries with strong British or English-language influence. This includes the United States, Canada, Australia, New Zealand, Ireland, the United Kingdom, and several South Asian nations such as India, Pakistan, and Bangladesh.

In these countries, everyday speech, media, and consumer-facing time displays commonly use the 12-hour format. However, even in these cases, 24-hour time remains standard in military operations, aviation, healthcare systems, and public transportation. The difference is largely cultural and conversational rather than administrative.