Timestamp Converter
Convert between Unix timestamps and human-readable dates with snippets for multiple systems.
const unixTs = 1774429399; const date = new Date(unixTs * 1000); const iso = date.toISOString(); // 2026-03-25T09:03:19.467Z
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC (the Unix epoch). It's a universal, timezone-independent way to represent a point in time. Tip: JavaScript uses milliseconds (multiply by 1000), while most other languages use seconds.
How do I get the current timestamp in JavaScript?
Use Date.now() for milliseconds or Math.floor(Date.now() / 1000) for seconds. In Node.js: process.hrtime() for high-resolution timing. Tip: always store timestamps in UTC and convert to local time only for display to avoid timezone bugs.
What is ISO 8601 date format?
ISO 8601 is the international standard for date/time strings: 2024-01-15T14:30:00Z. The 'T' separates date and time, 'Z' means UTC. Offsets like +02:00 indicate timezone. Tip: use ISO 8601 for APIs and data exchange — it's unambiguous and sorts correctly as a string.
What is the Year 2038 problem?
32-bit systems store Unix timestamps as a signed 32-bit integer, which overflows on January 19, 2038 at 03:14:07 UTC. Most modern systems use 64-bit timestamps. Tip: if you're building long-lived systems, ensure your database columns and APIs use 64-bit integers or proper datetime types.
How do I convert between timezones?
In JavaScript, use the Intl.DateTimeFormat API with the timeZone option, or libraries like date-fns-tz. Never calculate timezone offsets manually — they change with DST. Tip: store all timestamps as UTC; convert to the user's local timezone only in the presentation layer.