Time FAQs

General questions about measuring and displaying time.

Exact Time & Accuracy FAQs

What is the exact time right now?

How is the "correct" time officially determined?

Is the time on my computer or phone always accurate?

How often does an atomic clock lose a second?

Why is there a difference between solar time and clock time?

Clock Formats FAQs

What is the difference between AM/PM and 24-hour time?

Why do some countries use military time?

How do I convert 24-hour time to 12-hour time?

What does "12:00 PM" actually mean (noon or midnight)?

Synchronization FAQs

How do I sync my device with an atomic clock?

What is NTP (Network Time Protocol)?

Why does my clock drift or lose time over several weeks?

Does my watch stay accurate when I travel?

Seconds & Leap Seconds FAQs

What is a "Leap Second" and why do we need them?

How long is a second officially defined?

When was the last leap second added?

Are leap seconds being phased out?