Question 1

What is a Unix timestamp?

Accepted Answer

The number of seconds (or milliseconds) elapsed since January 1, 1970 00:00:00 UTC — the "epoch" — used throughout logs, APIs, and databases as a compact, timezone-agnostic way to represent a point in time.

Question 2

Why did my number convert to a date decades off?

Accepted Answer

You likely pasted a millisecond timestamp into the seconds field, or vice versa — a 13-digit number is almost always milliseconds, a 10-digit number is almost always seconds. Use the Auto button to detect which.

Question 3

Does JavaScript have the Year 2038 problem?

Accepted Answer

No — that problem is specific to systems storing time as a 32-bit signed integer of seconds. JavaScript's Date uses a 64-bit float of milliseconds, safely covering roughly ±273,000 years from 1970.

Question 4

What's the difference between the Local and UTC views?

Accepted Answer

Local shows the time in your browser's own timezone; UTC shows the same instant with zero offset — useful when comparing timestamps across servers or logs from different regions.

Question 5

Is anything I type here sent anywhere?

Accepted Answer

No — every conversion uses JavaScript's built-in Date and Intl APIs, computed entirely in your browser.

Unix Timestamp Converter

Frequently asked questions