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.
Epoch, Unix time, and timestamp — the same number
Four different names get used for one number, which is why this conversion confuses people more than it should.
| Name you will see | What it means |
|---|---|
| Unix time, Unix timestamp | Seconds elapsed since 1 January 1970, 00:00:00 UTC |
| Epoch time, Unix epoch | Identical — “the epoch” is that 1970 moment |
| POSIX time | Identical, the formal standard name |
| Milliseconds since epoch | The same count × 1000 — used by JavaScript and Java |
So a unix time epoch converter, an epoch converter and a timestamp to epoch converter all do the same job: turn that running count of seconds into a readable date, or the reverse.
Seconds or milliseconds?
The most common mistake is feeding a millisecond value into a tool expecting seconds, which throws the date roughly 50,000 years into the future. A quick check: a current timestamp in seconds is 10 digits; in milliseconds it is 13. This converter detects the length and handles both.
UTC and your local time
Epoch time is always UTC — it carries no timezone. The timezone only appears when you format it for display, which is why the same timestamp shows different clock times in London and New York, and why a value can look an hour out during British Summer Time. Store UTC, convert only at the point of display.
Frequently asked questions
It converts between Unix epoch time — the number of seconds since 1 January 1970 UTC — and a human-readable date. Unix time, epoch time, POSIX time and Unix timestamp all refer to the same number, so an epoch converter and a Unix timestamp converter are the same tool.
Count the digits. A current timestamp in seconds is 10 digits; in milliseconds it is 13. JavaScript's Date.now() and Java return milliseconds, while most Unix tools, databases and APIs use seconds. Passing milliseconds to a seconds-based converter puts the date tens of thousands of years in the future.
Epoch time is always UTC and carries no timezone. If the result looks an hour out, you are almost certainly seeing UTC where you expected British Summer Time, or vice versa. Store timestamps in UTC and apply the timezone only when formatting for display.
There is none — they are two names for the same value. “The epoch” is the reference moment (1 January 1970, 00:00:00 UTC) and Unix time is the count of seconds since it. POSIX time is the formal standard name for the same thing.
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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