Unix Timestamp Converter
Convert Unix timestamps to readable dates and vice versa. Supports seconds and milliseconds. See UTC and local time side by side. Browser only.
Unix Timestamp Converter
Runs entirely in your browser — no server calls, no tracking.
Click "Use current time" or paste a timestamp.
🔒 Your data never leaves this tab. This tool has no backend.
About the Unix Timestamp Converter
A Unix timestamp is the number of seconds (or milliseconds in JavaScript) elapsed since the Unix epoch — midnight on 1 January 1970 UTC. It is the universal time representation used in databases, logs, APIs, and distributed systems because it is timezone-agnostic, compact, and sortable. This tool converts between Unix timestamps and human-readable dates, and shows both UTC and local time side by side.
Seconds vs milliseconds
POSIX timestamps (used in Unix, Linux, Python's time.time(), SQL EXTRACT(EPOCH FROM ...)) are in seconds — typically 10 digits. JavaScript's Date.now() and many web APIs return milliseconds — 13 digits. When a timestamp looks wrong by exactly 1000x, you are mixing the two. The auto-detect mode in this tool identifies 10-digit values as seconds and 13-digit values as milliseconds.
ISO 8601 format
ISO 8601 is the international standard for date and time: 2026-07-06T14:30:00Z. The Z suffix indicates UTC. Without a timezone offset, parsers may interpret it as local time or UTC depending on the runtime — always include a timezone in date strings passed between systems. ISO 8601 sorts correctly as a string, which makes it useful in filenames and log entries.
Year 2038 problem: 32-bit signed integers overflow at Unix timestamp 2,147,483,647 (19 January 2038). Modern systems use 64-bit integers, but legacy embedded systems and 32-bit databases may be affected. JavaScript uses 64-bit floats, which accurately represent timestamps until the year 275,760 — effectively not an issue.
Frequently asked questions
new Date() expects milliseconds. new Date(1720268400) gives a date in 1970 because 1,720,268,400 milliseconds is only about 20 days after epoch. The correct call is new Date(1720268400 * 1000) or new Date(1720268400000). Another cause: missing timezone offset in an ISO string interpreted as local time vs UTC.Math.floor(Date.now() / 1000) (seconds) or Date.now() (ms). Python: import time; int(time.time()). Node.js: Math.floor(Date.now() / 1000). PHP: time(). SQL (PostgreSQL): EXTRACT(EPOCH FROM NOW()). SQL (MySQL): UNIX_TIMESTAMP().2026-07-06T14:30:00Z) is human-readable and unambiguous about timezone when the offset is included. Use it in UI text, logs intended for humans, and exported data files. Use Unix timestamps for inter-service communication, database storage, sorting, and arithmetic — they are smaller and avoid timezone parsing bugs.Need distributed systems or scheduling built?
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