Armies started using the 24-hour method of timekeeping as standard military time because, much like police, fire, and medical departments, every branch of the armed services is in continuous operation ...

If you’re guilty of accidentally setting your alarm on your smartphone for 6 p.m. instead of 6 a.m. — you’re not alone. Most Americans prefer the a.m.-p.m. system instead of the 24-hour clock. But why ...