Question 1

How do I convert a Unix timestamp to a human-readable date?

Accepted Answer

Paste the Unix timestamp (seconds since January 1, 1970 00:00:00 UTC) into the converter. It automatically detects seconds (10 digits), milliseconds (13 digits), or microseconds (16 digits) and converts to both UTC and your local timezone.

Question 2

What is the difference between Unix timestamps in seconds and milliseconds?

Accepted Answer

Seconds timestamps are 10 digits (e.g., 1706745600), milliseconds are 13 digits (e.g., 1706745600000). JavaScript Date.now() and Java System.currentTimeMillis() return milliseconds. Python time.time() and most Unix systems use seconds.

Question 3

What is the Unix epoch and the Y2K38 problem?

Accepted Answer

The Unix epoch is January 1, 1970 00:00:00 UTC — the zero point for all Unix timestamps. The Y2K38 problem occurs because 32-bit signed integers overflow on January 19, 2038 (max value 2,147,483,647). Modern 64-bit systems avoid this by using 64-bit timestamps.

Question 4

How do I debug JWT exp and iat claims?

Accepted Answer

JWT exp (expiration) and iat (issued at) claims are Unix timestamps in seconds. Paste the numeric value from your JWT payload into this converter to see the exact date and time, then compare with the current time to check if the token is valid or expired.

Unix Timestamp Converter Online - Epoch to Date Free Tool

Written by IAMDevBox

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