Since the 24-hour clock (00:00–23:59) uses four-digit numbers, some of them match real years in history. That means every day, as the clock ticks, you're seeing reminders of past events without even realizing it.
For example:
19:45 (7:45 PM) = 1945 → The end of World War II.
18:12 (6:12 PM) = 1812 → The War of 1812 begins.
14:53 (2:53 PM) = 1453 → Fall of Constantinople.
08:00 (8:00 AM) = 800 → Charlemagne crowned Holy Roman Emperor.
Since a clock can only show minutes up to :59, this limits the possible years to ones between 0000 and 2359. That means some famous years (like 1776 or 1492) won’t appear because they have numbers too high for minutes.
This fun way of looking at time lets you connect everyday moments with history. Most clocks have the 24-hour option (but sadly Microsoft seems to have abandoned the 24-hour clock in Windows 10/11 (but perhaps if this article falls across the eyes of someone at Microsoft, this function will return overnight.))
The 24-hour clock goes by a few different names depending on the context:
Military Time – Commonly used in the military and other governmental services to avoid confusion between AM and PM times.
Zulu Time – Refers to UTC (Coordinated Universal Time), especially in aviation. The term "Zulu" comes from the phonetic alphabet, where "Z" represents Zero time, meaning UTC.
European Time – In many European countries, the 24-hour clock is just called "time" in daily use, as it’s the standard for all scheduling and timekeeping.
Railroad Time – Historically used in the United States for train schedules, which were usually based on the 24-hour clock to prevent confusion and avoidable accidents.
International Time – Used especially in contexts like international travel and communication, where clarity across time zones is crucial.
Standard Time – A generic term sometimes used for the 24-hour format, as it’s often the "standard" in professional and scientific settings.
It’s basically the clock that all other countries run on outside of North America’s fascination with the AM/PM clock (except Quebec). I encourage people to change their clocks wherever possible and stand united against the inferior AM/PM that is ubiquitously used (for the history of AM/PM, see below) *.
Here are some more ideas that will inevitably catch your eye when you next look at your clock:
20:25 (8:25 PM) = 2025 – The present year, history in the making.
20:23 (8:23 PM) = 2023 – AI revolution (ChatGPT, Midjourney, etc.).
20:11 (8:11 PM) = 2011 – Osama bin Laden killed.
19:45 (7:45 PM) = 1945 – End of WWII.
19:18 (7:18 PM) = 1918 – End of WWI.
18:12 (6:12 PM) = 1812 – War of 1812 begins.
17:59 (5:59 PM) = 1759 – British capture Quebec in the Seven Years' War.
16:49 (4:49 PM) = 1649 – Execution of King Charles I of England.
15:57 (3:57 PM) = 1557 – First paper money introduced in Ming China.
14:53 (2:53 PM) = 1453 – Fall of Constantinople to the Ottoman Empire.
13:13 (1:13 PM) = 1313 – Programmers' code (Leek). Google it if inclined.
13:12 (1:12 PM) = 1312 – Dissolution of the Knights Templar.
12:07 (12:07 PM) = 1207 – Mongol conquests begin under Genghis Khan.
11:59 (11:59 AM) = 1159 – Henry II becomes Holy Roman Emperor.
10:06 (10:06 AM) = 1006 – Supernova SN 1006, the brightest in recorded history.
09:59 (9:59 AM) = 959 – Edgar the Peaceful becomes King of England.
08:00 (8:00 AM) = 800 – Charlemagne crowned Holy Roman Emperor.
06:22 (6:22 AM) = 622 – Start of the Islamic calendar (Hijra).
04:59 (4:59 AM) = 459 – End of the Western Roman Empire.
03:59 (3:59 AM) = 359 – Roman Emperor Constantius II dies.
02:59 (2:59 AM) = 259 – Beginning of the Crisis of the Third Century in Rome.
01:59 (1:59 AM) = 159 – Antonine Plague devastates Rome.
00:59 (12:59 AM) = 59 – Roman Emperor Nero begins rule.
16:20 (4:20 PM) = 420 – Global Pot smoking time started at UCLA.
*(To be fair, the AM/PM delineation is ancient, in fact the 12-hour clock can be traced back as far as Mesopotamia and ancient Egypt. Both an Egyptian sundial for daytime use and an Egyptian water clock for night-time use were found in the tomb of Pharaoh Amenhotep I. Dating to c. 1500 BC, these clocks divided their respective times of use into 12 hours each. It is still the gold standard for boring clock clichés.)