What Is a Unix Timestamp, and How Do You Convert It?

A Unix timestamp is a single number representing a point in time — the count of seconds that have elapsed since 00:00:00 UTC on January 1, 1970 (the "Unix epoch"). Instead of storing a date as text with a timezone attached, systems store this one plain number and format it however they need at display time.

Why systems use it instead of a normal date string

A timestamp is timezone-agnostic, sortable as a plain number, and unambiguous across every system and programming language — there's no "is this MM/DD/YYYY or DD/MM/YYYY" confusion, because it's just seconds counted from a fixed reference point. That's why it shows up everywhere in logs, databases and API responses instead of a human-readable date.

Seconds vs milliseconds — the most common mix-up

Step-by-step: converting a timestamp

1. Open the Timestamp Converter.
2. Paste your timestamp — check whether it's 10 digits (seconds) or 13 digits (milliseconds) if the tool doesn't detect it automatically.
3. Read the converted human-readable date and time, shown in your local timezone and in UTC.
4. To go the other direction, enter a date and get back the Unix timestamp — handy for constructing API requests or database queries that expect one.

A quick way to sanity-check by hand

As a rough mental check: timestamps in the 1,700,000,000s to 1,800,000,000s range correspond to dates in 2023–2026. If you're staring at a number wildly outside that range while expecting a recent date, you're very likely looking at milliseconds (or microseconds) rather than seconds — divide by 1,000 (or 1,000,000) and check again.