A two-way converter between Unix timestamps (epoch time) and human-readable dates. Use it when you find a number like `1700000000` in a log or database and need to know when that is, or when you need to turn a specific date into Unix time to paste into code or a query. You can set the input unit explicitly to seconds or milliseconds, or pick "Auto" to infer it from the digit count (13+ digits is treated as milliseconds). Results are shown in both UTC and your device's local time, as an ISO 8601 string like `2024-01-02T03:04:05.000Z`, and as a relative phrase such as "3 minutes ago" or "in 2 days". A time-zone toggle switches between Local and UTC, which also controls how the wall-clock time you type is interpreted when converting a date back to Unix time. The top of the page shows the current epoch in seconds and milliseconds, updated every second, with one-click copy — handy for grabbing a "now" value or test data. Your unit and time-zone choices are saved in your browser so it opens the same way next time. Importantly, neither the values you enter nor the results are ever uploaded, stored, or sent to a server — all computation happens with JavaScript's `Date` / `Intl` entirely inside your browser, so it's safe to use with internal logs or timestamps. Because mixing up seconds and milliseconds is a classic bug, the unit is made explicit.