What epoch time is
Unix time counts seconds since 00:00:00 UTC on 1 January 1970 — the "epoch." It's timezone-free by definition, which is exactly why systems store it and humans can't read it. A 10-digit number is seconds; 13 digits means milliseconds (JavaScript's native unit); 16 and 19 digits are micro- and nanoseconds from high-resolution systems — divide accordingly.
Timestamps worth recognizing
0 is the epoch itself; 86400 is exactly one day; 1000000000 fell in September 2001 and 1500000000 in July 2017. The famous one is 2147483647 — 19 January 2038 — where signed 32-bit counters overflow (the "Year 2038 problem"); modern 64-bit systems are safe for another 292 billion years.
Frequently asked questions
How do I know if a timestamp is seconds or milliseconds?
Count digits: current times are 10 digits in seconds and 13 in milliseconds. This converter auto-detects by length and tells you which it assumed.
Why does the date shown differ from my coworker's?
The timestamp itself is timezone-free; only the human rendering differs. This page shows your local time, UTC, and ISO 8601 together so cross-timezone comparisons stay honest.
What is the Year 2038 problem?
Signed 32-bit Unix time overflows at 2147483647 — 03:14:07 UTC on 19 January 2038. Systems still storing time in 32 bits will wrap to 1901; modern platforms moved to 64-bit long ago.
How do I get the current timestamp in code?
JavaScript: Date.now() (ms) or Math.floor(Date.now()/1000). Python: time.time(). SQL: strftime('%s') in SQLite, EXTRACT(EPOCH FROM now()) in Postgres. Or copy the live value above.