Unix Timestamp Converter Convert between Unix timestamps and human-readable dates in both directions.

The converter handles three timestamp formats: seconds (10 digits, standard Unix), milliseconds (13 digits, JavaScript Date.now()), and microseconds (16 digits, some logging systems). Auto-detection uses magnitude thresholds: values above 1e15 are treated as microseconds, above 1e12 as milliseconds, otherwise as seconds. The conversion uses JavaScript's Date constructor which accepts millisecond timestamps, so seconds are multiplied by 1000. The reverse conversion uses Date.getTime() for milliseconds and Math.floor(getTime() / 1000) for seconds. The live current timestamp uses a useEffect with a 1-second setInterval. Relative time descriptions are computed by comparing the timestamp to the current time and expressing the difference in the most appropriate unit.