Unix Timestamp Converter
Convert epoch time to a date and back — seconds, millis, micros & nanos
—
—
—
—
—
—
—
Time zones are the hard part
Unit auto-detection
Seconds, milliseconds, microseconds, and nanoseconds are detected automatically from the digit count, so a 10-digit epoch, 13-digit millis, and 19-digit nanos each resolve without touching the unit dropdown.
Four formats at once
One input produces local time, UTC, ISO 8601, and a relative reading like three days ago, while the header clock ticks live seconds and milliseconds — click either to drop it into the converter.
Dates back to epoch
The reverse direction converts a chosen date into epoch seconds, milliseconds, and the ISO string, so an API expecting either precision gets its value from the same form.
What Is a Unix Timestamp Converter?
A Unix timestamp counts the seconds — or milliseconds — since January 1st 1970 UTC, and it is the time format behind most APIs, logs, and databases. Reading 1754833920 as a calendar date by eye is impossible, and working out the right number for a specific date is just as error-prone. This converter handles both directions: paste a timestamp and get local time, UTC, ISO 8601, and a relative time such as "3 days ago"; or pick a date and get the matching seconds, milliseconds, and ISO string. It auto-detects whether your input is seconds, milliseconds, microseconds, or nanoseconds, and you can override the guess manually. A live clock at the top shows the current epoch in both seconds and milliseconds, clickable to drop into the input. Built for developers, DevOps engineers, and anyone digging through logs.
What this tool can do
- 🕐 Live epoch clock showing current seconds and milliseconds
- 🔍 Automatic unit detection: seconds, ms, microseconds, or nanoseconds
- 🔄 Timestamp to date: local time, UTC, ISO 8601, and relative time
- 📅 Date to timestamp: seconds, milliseconds, and ISO output
- 📋 Copy any result with one click
When you will use it
- Reading a timestamp field in an API response or log line
- Generating an expiry timestamp for a test token
- Converting between UTC and local time while debugging
- Correlating relative and absolute times during an incident
Privacy: all conversions happen locally in your browser; your timestamps are never sent anywhere or recorded.
Epoch numbers versus ISO strings
Unix time counts seconds since 1970-01-01 UTC — deliberately zone-less. Everything zone-shaped happens when you render it:
- A bare number has no offset; the same 1700000000 is dinner in Berlin and lunch in New York.
- ISO 8601 strings carry their offset (Z or +08:00) — prefer them for storage, convert only for display.
- 10 digits = seconds, 13 digits = milliseconds: this tool auto-detects and says which it assumed.
Frequently asked questions
What is a Unix timestamp?⌄
It is the number of seconds (or milliseconds, microseconds, nanoseconds) elapsed since 00:00:00 UTC on 1 January 1970, the Unix epoch. It is timezone-independent, which makes it a compact, unambiguous way to store a moment in time.
How do you detect seconds vs milliseconds?⌄
By the number of digits: a 10-digit value is seconds, 13 digits is milliseconds, 16 is microseconds and 19 is nanoseconds. Automatic detection covers dates from 2001 to 2286; you can override the unit with the selector if your value falls outside that range.
Which timezone are the results in?⌄
The “Local” row uses your device timezone and locale via the Intl API; “UTC” and “ISO 8601” are always in UTC. The date-to-timestamp field interprets the date you pick in your local timezone.
Why does my timestamp shift by exactly one hour?⌄
Almost always a daylight-saving boundary. A wall-clock string like 2026-03-29 02:30 simply did not exist in Europe that year; parsers either jump forward an hour or pick a side depending on settings. Store UTC or full ISO offsets and the ambiguity disappears.