Binary & hex color clock
Tell the time the way a machine might. Read the hour in binary bits, or watch it drift through color as the hours, minutes, and seconds drive a live hex swatch.
The binary clock reads each digit of 24-hour time as vertical bits. The hex clock treats the hours, minutes, and seconds as the red, green, and blue channels of a color that shifts every second.
How to use the binary & hex color clock
Read the columns
Each column is one digit of the time in binary-coded decimal. A lit cell is a 1; add the row values in a column to get that digit.
Learn the row weights
From the bottom up the rows are worth 1, 2, 4 and 8. A column with the 4 and 1 rows lit reads 5.
Read the hex colour clock
The same time is expressed as a colour: hours, minutes and seconds become the red, green and blue channels of a hex value that shifts continuously through the day.
Practise
Compare against the digital readout until you stop needing it — reading BCD fluently takes an afternoon.
Binary-coded decimal, and time as a colour
Almost every binary clock uses binary-coded decimal rather than a plain binary number. Each decimal digit is encoded separately in four bits, so 15:42 is displayed as four columns — 1, 5, 4, 2 — rather than as one binary value. It uses more cells than pure binary would, but it is far easier to read, because you decode one small digit at a time.
BCD is not just a clock novelty. It was widely used in early computing and remains standard in real-time clock chips, calculators and financial systems, for a specific reason: converting to a displayable decimal string is trivial, and decimal fractions do not suffer the rounding error that binary floating point introduces. When money is involved, that matters.
The hex colour clock is a different idea: interpret the time directly as a colour. 15:42:07 becomes #0F2A07 — hours, minutes and seconds as the red, green and blue channels. The result is a colour that shifts continuously through the day and is exactly readable if you know the encoding, which makes it an unusually elegant ambient display.
Both are, ultimately, arguments that a clock face is a rendering choice rather than a fixed thing. The instant is the same; twelve-hour dials, 24-hour digits, binary columns and hex colours are just different projections of it.
When it comes in handy
Learning binary.
A live, self-correcting exercise in reading BCD.Desk ornament.
A clock that only the people who know how to read it can read.Teaching number bases.
The same value in decimal, binary and hexadecimal, updating every second.Ambient display.
The colour clock as a slowly shifting background on a spare screen.Design inspiration.
A reference for encoding data as colour.Conversation piece.
The original geek clock, still doing its job.
Questions & answers
- How do I read a binary clock?
- Each column is one digit of 24-hour time in binary, most-significant bit at the top. Add the lit dots' values (1, 2, 4, 8 from the bottom up) to read each digit.
- What is the hex color clock?
- It maps the hours, minutes, and seconds onto the red, green, and blue channels of a color — so the time 13:47:20 becomes #0D2F14. The color changes every second.
- Does it use my local time?
- Yes, both clocks read your device's local 24-hour time.
Related tools
- Decimal & Swatch Time — French Republican metric time and Internet .beats.
- 24-Hour Military Time Clock — Unambiguous global time in a strict 24-hour format.
- Analog & Digital Multi-City Clocks — Classic dials and crisp readouts for every timezone you follow.
- ISO 8601 Generator & Decoder — Build and read strict timestamps without guesswork.
- Unix Epoch Converter — Seconds, milliseconds, microseconds — decoded instantly.
- Live World Clock Dashboard — Track any set of cities side by side, with day and night at a glance.