Q&A for How to Read a Binary Clock

A dot clock is just another word for a binary clock. Sometimes they’re also called 10-bit clocks. Use the techniques outlined in this article to decode the time on your dot clock.

It depends on the watch. Most binary watches have one or more button that you can use to set the hours, minutes, and seconds. Check your user’s manual to determine how to set your watch. If you don’t read binary, you’ll need a guide to help you determine the correct arrangement of dots in each column.

When reading binary, remember that each number is represented by a group of 8 digits, which are either 0s or 1s (or, in the case of a binary clock, dark or light dots). You read each group from right to left. Every digit in the group represents 2 to the power of n, with n being that digit’s position in the row. For example, the first digit to the right is 2 to the power of 0 (or 1), while the leftmost digit is 2 to the power of 8 (256). A 1 in a particular position indicates that you read that number, while a 0 means that number is absent. Add up any numbers that are “active” (represented by 1s) to read a binary grouping. For example, 00000010 = 2, while 00000101 = 9.

To represent negative numbers in binary, you normally use Two's Complement. To calculate a negative number in Two's Complement, you calculate the positive number, flip the bits, and add one. For -15, you first calculate 15: 0 1111 (you need the extra bit, as the MSB represents the sign), flip them: 1 0000, and add 1: 1 0001.

Just look at the time on a different device after solving it. For example, if you just read 10:15 on the binary clock, just look at your phone's time to see if you read it correctly.

You would use them because they look nice, and they don't use as much power.