# How to Read a Binary Clock Display

Binary clocks display the time digitally using the base-2 representation of numbers. In binary, only 1's and 0's are used to form numbers. A sleek binary clock display has 3 columns (or rows, depending on how the clock is oriented). The first column displays the current hour, the middle column displays the minutes, and the last column displays the seconds. The hour column has four lights, since 12 has four digits in binary and 12 is the largest hour number. The minutes and seconds columns each have six lights, since 59 has six digits in binary and 59 is the highest number of minutes or seconds.

When a light is on, it represents 1, and when a light is off, it represents 0. The bottom row of lights represents 20 = 1, the next row represents 21 = 2, and so on until the top row, which represents 25 = 32. The image below shows how 10:25:46 is shown on a binary clock.

The binary representation of 10 is 1010, the binary form of 25 is 11001, and the binary form of 46 is 101110. One of the nice visual features of a binary clock is that the seconds column changes every second, so the clock blinks.

Another style of binary clock has six columns. The first two columns display the two digits of the hour, the middle columns display the two digits of the minutes, and the last two columns show the digits of the seconds. Use the table below as an aid when converting a decimal number to binary. Learning how to read a binary clock takes a little practice, but once you get comfortable with the number system, you will start to memorize the patterns.

 0 0 15 1111 30 11110 45 101101 1 1 16 10000 31 11111 46 101110 2 10 17 10001 32 100000 47 101111 3 11 18 10010 33 100001 48 110000 4 100 19 10011 34 100010 49 110001 5 101 20 10100 35 100011 50 110010 6 110 21 10101 36 100100 51 110011 7 111 22 10110 37 100101 52 110100 8 1000 23 10111 38 100110 53 110101 9 1001 24 11000 39 100111 54 110110 10 1010 25 11001 40 101000 55 110111 11 1011 26 11010 41 101001 56 111000 12 1100 27 11011 42 101010 57 111001 13 1101 28 11100 43 101011 58 111010 14 1110 29 11101 44 101100 59 111011