Binary Clock 24 App

Challenge your brain. Binary Clock 24 is a free app that displays time using a binary system.


The Binary Clock 24 iOS app was designed to:

  • Display time (hours, minutes, seconds) in a binary format
  • Challenge your brain
  • Provide a minimal black and white interface

How Does Binary Clock Work?

There are 3 rows of white and/or black circles. The top row are the hours (24 hour format), the middle row are the minutes and the bottom row the seconds.

A binary number can only have 2 states, such as on or off, true or false, yes or no. In the app, the on state is a filled white circle and the off state is a black circle with a white outline.

From left to right, the white circles in a row represent the numbers 32, 16, 8, 4, 2 and 1. To read the time, add all the white circle numbers in a row. Black circles represent the number 0.

Example 1

If only the 2 and 1 white circles are on in the first row, the time would be:

Example 2

If only the 32, 8 and 2 white circles are on in the middle row, then the time would be:

Example 3

If there are no white circles on in the bottom row, the time would be 0 seconds.

24 Hour Format

The following is a table with some 12 hour clock conversions to a 24 hour format (also known as military time).

12 Hour Clock 24 Hour Military Time
9 a.m. 9:00
11 a.m. 11:00
1 p.m. 13:00
2 p.m. 14:00
3 p.m. 15:00
4 p.m. 16:00
5 p.m. 17:00
6 p.m. 18:00
7 p.m. 19:00
8 p.m. 20:00
9 p.m. 21:00
10 p.m. 22:00
11 p.m. 23:00


Note that the first row (the hours) does not have a circle representing the number 32. It’s not required since there are only 24 hours in a day.

Tap anywhere on the clock then tap on the help button to access this page. Tap an empty area to return to the clock.

Download Binary Clock 24 and impress your friends with how you can tell the time just like a computer!

Download Binary Clock 24 on the App Store

Binary Clock 24 screenshots and examples

Download Binary Clock 24 on the App Store

Binary Clock 24 Version 1.00, December 2018
Copyright © 2018-2019 Denis Desjardins

D Logo