Timestamp Converter Online

Enter a Unix timestamp in the top field and click Timestamp → Date to see the UTC, local, and ISO 8601 representations. Enter a date string in the bottom field and click Date → Timestamp to get seconds and milliseconds. Click Now to prefill the current local time.

What is a Unix timestamp?

A Unix timestamp (also called epoch time or POSIX time) is the number of seconds elapsed since January 1, 1970 at 00:00:00 UTC — known as the Unix epoch. It is the most widely used time representation in programming because it is timezone-independent, easy to store as a single integer, and simple to compare and do arithmetic with.

Example: the timestamp 1700000000 = November 14, 2023 at 22:13:20 UTC.

Seconds vs milliseconds

Most Unix APIs (C, Python, shell) use seconds. JavaScript's Date.now() and many modern APIs use milliseconds — the same moment as a milliseconds timestamp has 13 digits instead of 10. This tool auto-detects: values greater than 9,999,999,999 are treated as milliseconds.

Code examples

// Current timestamp
const seconds = Math.floor(Date.now() / 1000);   // e.g. 1700000000
const millis  = Date.now();                        // e.g. 1700000000000

// Timestamp → Date
const d = new Date(1700000000 * 1000);
console.log(d.toISOString());   // "2023-11-14T22:13:20.000Z"
console.log(d.toLocaleString()); // local time

// Date string → timestamp
const ts = Math.floor(new Date('2024-01-15T12:00:00Z').getTime() / 1000);

import time
from datetime import datetime, timezone

# Current timestamp
ts = int(time.time())             # seconds
ts_ms = int(time.time() * 1000)  # milliseconds

# Timestamp → datetime
dt = datetime.fromtimestamp(1700000000, tz=timezone.utc)
print(dt.isoformat())  # "2023-11-14T22:13:20+00:00"

# datetime → timestamp
ts = int(datetime(2024, 1, 15, 12, 0, 0, tzinfo=timezone.utc).timestamp())

Frequently asked questions

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