Epoch / Timestamp Converter

Unix epoch time is a way of representing a moment as a single number: the count of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, known as the epoch. This converter translates those numbers into readable calendar dates and back again, so you can decode a value pulled from a log file, database, or API response without doing arithmetic by hand.

How to use it

1. Paste one or more timestamps into the input. The tool accepts a single value or many at once, one per line, for batch conversion.
2. Confirm whether your values are in seconds or milliseconds. A 10-digit number is almost always seconds; a 13-digit number is milliseconds.
3. Read the converted human-readable date, shown in both UTC and your local timezone.
4. To go the other way, enter a calendar date and time and read off the matching epoch value to copy into your code or query.

Seconds, milliseconds, and timezones

The epoch count is timezone-independent: a given epoch number refers to the exact same instant everywhere on Earth. The differences appear only when that instant is formatted as a date. The same value renders as one wall-clock time in London and another in New York, which is why this tool shows UTC alongside your local result.

Granularity is the other common pitfall. Unix tools and many databases store epoch values in whole seconds, while JavaScript and many web APIs use milliseconds. Mixing the two produces dates that are wildly wrong, usually off by a factor of roughly a thousand. Checking the digit count before converting avoids this.

Unit	Typical digits	Example
Seconds	10	1700000000
Milliseconds	13	1700000000000

FAQ

Why are timestamps stored as numbers instead of dates?

A single integer is compact, sorts correctly, and is free of formatting, language, and timezone ambiguity. Storing one universal number and formatting it for display only when needed keeps systems consistent across servers and regions.

What does the epoch starting in 1970 mean?

1 January 1970 UTC is the agreed zero point for Unix time. Values before that date are represented as negative numbers, and values after it as positive numbers counting upward.

Should I use seconds or milliseconds?

It depends on the system you are feeding. Traditional Unix utilities and SQL databases expect seconds, while browser JavaScript and many modern APIs expect milliseconds. Match whatever the receiving system documents.

Is the result affected by daylight saving time?

The epoch number itself is not, but its local rendering is. When a date is shown in your local timezone, daylight saving rules are applied so the displayed clock time reflects the offset in force on that date.