What is the difference between seconds and milliseconds in a timestamp?

A 10-digit Unix timestamp represents seconds. A 13-digit timestamp represents milliseconds (1000x more precise). JavaScript's Date.now() returns milliseconds, while most Unix systems and languages default to seconds. This converter auto-detects the format based on the number of digits.

What is the Year 2038 problem?

Systems that store Unix timestamps as a signed 32-bit integer will overflow on January 19, 2038 at 03:14:07 UTC (timestamp 2147483647). Modern systems use 64-bit integers, which won't overflow until the year 292 billion.

How do I get the current Unix timestamp in different programming languages?

Why does my timestamp show the wrong time?

Unix timestamps are always UTC-based. If your converted time looks off by a fixed number of hours, you're likely confusing UTC with your local timezone. Use the timezone selector to convert to your local time, or make sure you're comparing to UTC.

// epoch converter

Unix Timestamp Tools

Q: What is a Unix timestamp?

A Unix timestamp is the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC (the Unix Epoch). It is a timezone-independent way to represent a specific point in time, widely used in databases, APIs, server logs, and programming languages.

Current Unix Time

// 01 — Epoch → Human-readable date

Unix Timestamp

Timezone

Supports seconds (10 digits), milliseconds (13), microseconds (16), nanoseconds (19) — auto-detected

Invalid timestamp. Please enter a numeric Unix timestamp.

UTC / GMT

—

Local Time

—

Selected Timezone

—

Relative

—

ISO 8601

—

Day of week / Week

—

// 02 — Date → Epoch timestamp

Year

Month

Day

Hour

Min

Sec

Timezone

Epoch (seconds)

—

Epoch (milliseconds)

—

ISO 8601

—

Day of week

—

Please check the values — year (1970–9999), month (1–12), day (1–31), hour (0–23), min/sec (0–59).

Or paste a date string:

Could not parse that date string.

// 03 — Epoch range for year / month / day

Year

Month (optional)

Day (optional)

Start (UTC)

—

End (UTC)

—

Start timestamp

—

End timestamp

—

// 04 — Convert seconds to years, months, days, hours, minutes

Seconds

86400 = 1 day · 604800 = 1 week · 2629800 = ~1 month · 31536000 = 1 year

// 05 — Batch timestamp conversion

One timestamp per line. Paste from logs, databases, or APIs.

Timestamps (one per line)

Output timezone

What is a Unix timestamp?

A Unix timestamp (also called epoch time, POSIX time, or Unix time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC — a reference point known as the Unix Epoch. It's a single integer, completely independent of timezones and daylight saving time.

Because it's just a number, timestamps are extremely efficient for databases to store, sort, and compare. You'll encounter them in API responses, server logs, JWT tokens, SQL databases, file system metadata, and virtually every modern software system.

Seconds vs milliseconds — how to tell them apart

The most common source of confusion with Unix timestamps is the difference between seconds and milliseconds. This converter auto-detects the format based on digit count:

10 digits = seconds

Standard Unix time. Example: 1776422400. Used by most Unix/Linux systems, Python's time.time(), PHP's time(), and SQL's UNIX_TIMESTAMP().

13 digits = milliseconds

JavaScript's default. Example: 1776422400000. Used by Date.now(), Java's System.currentTimeMillis(), and most browser APIs.

16 digits = microseconds

Used in high-precision systems, some databases (PostgreSQL), and hardware timing. Example: 1776422400000000.

19 digits = nanoseconds

Used in Go's time.Now().UnixNano() and high-frequency trading systems. Example: 1776422400000000000.

Current timestamp in common programming languages

JavaScript / Node.js

Math.floor(Date.now() / 1000)
or Date.now() for ms

Python

import time
int(time.time())

PHP

time()
or microtime(true)

SQL

MySQL: UNIX_TIMESTAMP()
PostgreSQL: EXTRACT(EPOCH FROM NOW())

Go

time.Now().Unix()
or .UnixMilli()

Java / Kotlin

Instant.now().getEpochSecond()

Frequently asked questions

What is the Unix Epoch and why is it January 1, 1970?

The date was chosen by early Unix developers at Bell Labs in the late 1960s as a convenient round number close to when Unix was being developed. It predates the widespread adoption of computers, making it a safe "zero point." The choice was somewhat arbitrary — it just needed to be a fixed point in the past that was easy to work with.
What is the Year 2038 problem?

Systems that store Unix timestamps as a signed 32-bit integer can only represent values up to 2,147,483,647 — which corresponds to January 19, 2038 at 03:14:07 UTC. After that point, the integer overflows to a large negative number. Modern systems use 64-bit integers, which can store timestamps until approximately the year 292 billion, effectively eliminating the problem.
Why does my converted timestamp show the wrong time?

Unix timestamps are always UTC-based. If your result is off by a fixed number of hours, you're likely confusing UTC with your local timezone. Use the timezone selector in the converter to display the time in your preferred timezone. Also check whether your timestamp is in seconds or milliseconds — a millisecond timestamp interpreted as seconds will show a date in 1970.
Can Unix timestamps represent dates before 1970?

Yes. Negative Unix timestamps represent dates before January 1, 1970. For example, -86400 represents December 31, 1969. Most modern systems and languages support negative timestamps, though some older systems do not.
Do Unix timestamps account for leap seconds?

No. Unix time deliberately ignores leap seconds — every day is treated as exactly 86,400 seconds. This means Unix time is not a true representation of UTC, but it makes arithmetic much simpler. In practice, this difference (about 27 seconds as of 2024) is negligible for most applications.