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NTP Timestamp Converter

Convert NTP timestamps (seconds since January 1, 1900 UTC) to and from regular dates - useful for debugging Network Time Protocol packets.

Category: time
Use Case: Debugging NTP Packet Captures, Network Time Synchronization Troubleshooting, Computer Science Education
Privacy: 100% browser-based

Recommended Settings

Pro Tips

  • Edit either the NTP timestamp or the date/time field - the other one updates automatically
  • Use the Copy buttons to grab any value in the format you need, including Unix seconds, milliseconds, or ISO 8601
  • Click Use Current Time to instantly see the current moment represented in this format
  • This runs entirely in your browser - nothing you enter is sent to a server

Most Popular

Most users paste in a raw value from a database or log file to see what date and time it actually represents

When to Use This Tool

Debugging NTP Packet Captures

Convert a raw NTP timestamp into a readable date and time.

Network Time Synchronization Troubleshooting

Work backward from a known date to the equivalent NTP timestamp.

Computer Science Education

Quickly verify what a specific timestamp value actually represents.

Debugging Unexpected Date Values

Figure out why a timestamp value looks wrong by converting it to a human-readable date.

How It Works

1

Take the NTP timestamp you enter, which represents seconds elapsed since January 1, 1900 UTC, the epoch defined by the Network Time Protocol specification

2

Convert it to a standard Unix millisecond timestamp using the correct epoch offset and unit scale

3

Display the result in several common formats, and support converting in the opposite direction too

100% Private

Files never leave your device. All processing happens locally in your browser.

Lightning Fast

Powered by Client-side epoch arithmetic for optimal performance on modern browsers.

Open Source

Built with verified, open-source libraries. Fully transparent.

Frequently Asked Questions

What epoch does this format use?

Seconds elapsed since January 1, 1900 UTC, the epoch defined by the Network Time Protocol specification.

Why would I need to convert this format?

NTP (Network Time Protocol) is used to synchronize clocks across computer networks, and its timestamp field counts seconds since 1900 rather than the more common 1970 Unix epoch.

Is my data sent to a server?

No. All conversion happens entirely in your browser using JavaScript.

Does this account for timezones?

The underlying timestamp is timezone-independent (a single point in time), and the 'Date & Time' field shows it in your browser's local timezone alongside UTC for reference.

What if I enter an invalid value?

The tool will show a warning that the value doesn't look valid rather than silently displaying an incorrect date.