Unix Timestamp Converter

Epoch Time ↔ Human-Readable Date

Instantly convert Unix timestamps to readable dates and back. Auto-detects seconds or milliseconds, shows UTC, local time, ISO 8601, RFC 2822, and relative time, plus a visual timeline. All calculations happen in your browser — your data never leaves your device.

🔒 Calculated in your browser — your data never leaves your device

Current Unix Timestamp —

Timestamp Unit

Timestamp seconds

Date & Time local

Time format:

Conversion formula
Unix timestamp (seconds) × 1000 = JavaScript Date (milliseconds)

UTC
—
Coordinated Universal Time

Local Time

—

ISO 8601

—

YYYY-MM-DDTHH:mm:ssZ

RFC 2822

—

Email / HTTP header format

Relative

—

From now

Timeline — Epoch to Now

Jan 1, 1970 (Epoch) Now

Conversions use your browser's built-in Date object and your device's local timezone setting. Results are accurate to the second.

Reference Table — Common Timestamps

Timestamp (sec)	UTC Date	Event

How to Use the Unix Timestamp Converter

Enter a Timestamp or a Date

Type a Unix timestamp into the Timestamp field, or pick a date and time using the Date & Time field. The converter is fully bidirectional — entering a timestamp calculates the date instantly, and entering a date calculates the timestamp. No button press required.

Confirm the Unit

By default the tool auto-detects whether your number is in seconds (10 digits, the Unix standard) or milliseconds (13 digits, used by JavaScript and Java) based on length. Use the pill selector to force one or the other if you already know the unit.

Read Your Results and Timeline

The result cards show your converted date in UTC, your local timezone, ISO 8601, RFC 2822, and relative time. The visual timeline places your entered date on a line between the Unix Epoch (January 1, 1970) and right now, so you can see at a glance how far back — or forward — your timestamp sits.

Copy or Print Your Conversion

Click Copy Result to copy the primary UTC value to your clipboard. Click Print to generate a clean, printer-friendly summary that includes your result cards, the timeline, the calculation formula, and the reference table — all formatted for paper.

Frequently Asked Questions

What is a Unix timestamp?

A Unix timestamp (also called Unix time, POSIX time, or epoch time) is the number of seconds that have elapsed since January 1, 1970, at 00:00:00 UTC, not counting leap seconds. It is widely used by operating systems, databases, and APIs as a compact, timezone-independent way to represent a point in time.

How do I know if my timestamp is in seconds or milliseconds?

Count the digits. A 10-digit number such as 1700000000 is typically seconds, which is the Unix standard used by Python, PHP, and most databases. A 13-digit number such as 1700000000000 is typically milliseconds, used by JavaScript and Java. This tool detects the unit automatically based on length, with a manual override available via the pill selector.

What happens on January 19, 2038?

Systems that store Unix timestamps as signed 32-bit integers will overflow on January 19, 2038 at 03:14:07 UTC, rolling the value over to a negative number that gets misread as December 13, 1901. This is known as the Year 2038 problem. Most modern systems have already migrated to 64-bit timestamps, which will not encounter this issue for roughly 292 billion years.

Why are Unix timestamps always in UTC?

A Unix timestamp represents a single absolute instant in time, independent of timezone. Only its human-readable rendering depends on a timezone — the same timestamp displays as different wall-clock times in different locations, but it always refers to the same moment.

Can a Unix timestamp be negative?

Yes. Negative Unix timestamps represent dates before January 1, 1970. For example, -86400 represents December 31, 1969. Most systems and databases handle negative timestamps correctly, though some older or constrained systems may not.

Is my data safe when using this converter?

Yes. All calculations happen entirely in your browser using JavaScript's built-in Date object. No values you enter are ever transmitted to a server.