Convert between Unix epoch time (seconds since 1 January 1970 UTC) and a readable date, in your browser's own timezone and in UTC.
Unix time counts whole seconds elapsed since 1 January 1970, 00:00:00 UTC — commonly called "the epoch" — ignoring leap seconds entirely, which is why it's the standard way computers store a point in time internally: it's a single number, not a timezone-dependent string that needs parsing.
If you paste in a number larger than roughly 10 trillion, the converter treats it as milliseconds rather than seconds, since that's the timestamp format JavaScript's own Date object commonly produces — a helpful auto-detection that saves you from manually figuring out which unit a pasted timestamp is in.
Converting the other direction, typing a date and time into the local box reads it in your own device's timezone, then converts it into the timezone-independent Unix timestamp — useful for developers debugging logs, APIs, or databases that store times as raw Unix timestamps rather than human-readable dates.
The number of seconds elapsed since 1 January 1970, 00:00:00 UTC (the "epoch"), ignoring leap seconds. It's the standard way computers store a point in time internally, because it's just one number, not a timezone-dependent string.
Yes — if the number you paste is larger than roughly 10 trillion, it's treated as milliseconds (JavaScript's native timestamp unit) instead of seconds (the more common Unix convention), and converted accordingly.
Because the "your local time" figure depends on each device's own timezone setting. The underlying UTC time, and the epoch number itself, are identical everywhere — only the human-readable local rendering changes.
