Epoch ↔ date.

Convert a Unix timestamp to a readable date — UTC, your local time, ISO 8601, and relative — or a date back to epoch. It auto-detects seconds vs milliseconds so you never multiply by 1000 in your head.

The instant, in every frame

Timestamps trip people up because the same number means different things depending on units and timezone — a 10-digit value is seconds, a 13-digit one is milliseconds, and the human reading of it depends on where you are. Logs, tokens, database rows, and API responses are full of raw epoch values, and a quick, unambiguous conversion is one of the most common things a backend developer reaches for. Storing and passing ISO 8601 in UTC, and converting only at the edges, saves a whole class of off-by-one-timezone bugs.