Binary Clock
The time as binary dots — each of the six digits of HH:MM:SS shown as its own column of lit and unlit bits.
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About this tool
Shows the time as binary-coded decimal (BCD): each of the six digits in HH:MM:SS is converted separately into a 4-bit binary column, read bottom-to-top as 8-4-2-1, rather than the whole time being converted as one large binary number. This is the format most "binary clocks" use, since a single-number binary clock would need dozens of bits and be far harder to read at a glance.
- How do I read one column?
- Each column is one decimal digit. The dots represent, from bottom to top, the values 1, 2, 4 and 8; add up the value of every LIT dot in a column to get that digit. For example, only the bottom two dots lit means 1 + 2 = 3.
- Why are some rows always unlit?
- The tens digit of minutes and seconds only ever needs to count 0–5, so its top two bits (4 and 8) are never used and stay permanently unlit — that's expected, not a fault.