Epoch / Unix Timestamp Converter
Converts Unix epoch timestamps to human-readable dates — and dates back to epoch. Seconds and milliseconds are auto-detected. Every conversion runs in your browser.
Epoch → Date
Enter a valid numeric timestamp.
- UTC
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- Local time
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- ISO 8601
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- Relative
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- Day of week
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- Detected unit
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Date → Epoch
- Epoch (seconds)
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- Epoch (milliseconds)
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Frequently Asked Questions
What is Unix epoch time?
Unix epoch time (POSIX time) is the number of seconds elapsed since 1 January 1970 00:00:00 UTC. Because it is a single number independent of time zones, it is the timestamp standard in logs, APIs and distributed systems.
How do I tell seconds from milliseconds?
An epoch in seconds is 10 digits today; in milliseconds it is 13 digits. This tool auto-detects the unit from the digit count. Unix tools and most databases use seconds, while JavaScript's Date.now() uses milliseconds.
Why are epoch timestamps in UTC?
Epoch counts elapsed time since a fixed instant (1970 UTC); it carries no time zone. You convert it to local time for display, but always storing epoch (UTC) avoids bugs caused by time zones and daylight saving.
What is the year 2038 problem?
Systems that store epoch in a signed 32-bit integer overflow on 19 January 2038 at 03:14:07 UTC. Modern systems use a 64-bit integer, which gives a practically unlimited range. In .NET, DateTimeOffset does not suffer from this.
How do I produce an epoch in .NET?
DateTimeOffset.UtcNow.ToUnixTimeSeconds() gives the epoch in seconds, and ToUnixTimeMilliseconds() gives it in milliseconds. To convert back, use DateTimeOffset.FromUnixTimeSeconds(value).