How to write 10-40 am?

Understanding Time Formats: AM to Military Time

When you see 10:40 a.m. written out in standard 12-hour time, it simply means forty minutes past ten in the morning. However, shifting over to military time changes how we note the hours completely.

In military time—which mirrors the standard 24-hour clock used globally—the day runs continuously from 0000 at midnight up to 2359 just before the next day begins. Because of this continuous loop, terms like a.m. and p.m. become completely unnecessary.

To convert 10:40 a.m. into military format, you just drop the colon, drop the a.m., and write it as a straightforward four-digit string: 1040, pronounced "ten-forty" hours.