By Updated

Timestamp Converter

Convert between Unix timestamps, ISO 8601, RFC dates, and human-readable formats with timezone support

Interactive tool

Input

Display timezone

What is a Timestamp Converter?

A timestamp converter translates between Unix epoch values, ISO 8601 strings, and human-readable dates. It accepts seconds, milliseconds, and parseable date strings, and shows the result in UTC, local time, and any chosen timezone.

How to Use This Timestamp Converter

  1. 1Type or paste a Unix timestamp, ISO date, or any parseable date string
  2. 2Pick the display timezone if you want a specific zone
  3. 3Read off the converted formats including UTC, local, and ISO 8601
  4. 4Click Now to fill the input with the current epoch
  5. 5Use Copy on any field to copy that exact value
What you get

Key features

Auto-Detect Format

Detects Unix seconds, Unix milliseconds, ISO 8601, RFC 2822, and other parseable strings without needing a format setting

Multiple Output Formats

Shows Unix seconds, Unix milliseconds, ISO 8601 UTC and local, RFC 2822, and human-readable formats

Timezone Support

Pick from common IANA timezones to see the exact local moment in another part of the world

Now Button

One click fills the input with the current Unix timestamp

Live Conversion

Output updates as you type, no separate convert button needed

Calendar Insights

Shows weekday, day of year, ISO week of year, and relative time from now

Copy Each Format

Each output line has its own copy button for grabbing exactly the format you need

100% Private

Conversion runs in your browser. Nothing is uploaded

Why Convert Timestamps?

Logs, databases, and APIs commonly store dates as Unix epoch integers because they are unambiguous and timezone-free. Humans read dates in calendar form. Converting between the two is essential when debugging, correlating events across systems, or reading machine logs by hand.

Common use cases

  • Reading Unix timestamps from server logs and databases
  • Debugging API responses that include epoch fields
  • Translating ISO 8601 dates to local time for display
  • Verifying scheduled job execution times across timezones
  • Generating timestamps for test fixtures
  • Converting between seconds and milliseconds for system interop
  • Checking what day of the week a Unix timestamp falls on
  • Aligning events from logs in different timezones

Unix Seconds vs Milliseconds

JavaScript and many APIs use milliseconds. Most Unix systems and databases use seconds. The converter auto-detects: 13-digit numbers are treated as milliseconds, 10-digit and shorter numbers as seconds.

Timezones and Daylight Saving

Timezone offsets shift twice a year for many regions. The converter uses IANA timezone data so the displayed local time is correct including daylight saving rules. Pick the canonical zone (like America/Los_Angeles) rather than abbreviations to avoid ambiguity.

Pro tips

Tips & best practices

Use ISO 8601 for storage

ISO 8601 is human-readable, lexically sortable, and unambiguous. Prefer it for log lines and API payloads

Always include timezone

Bare local times invite bugs. Either store UTC and convert at display time, or include the offset in the ISO string

Watch the digit count

Unix seconds are 10 digits today; milliseconds are 13. Misreading the unit is a common source of off-by-1000 bugs

Pick canonical timezones

IANA names like America/New_York handle DST correctly. Abbreviations like EST and EDT can mean different things

Use the relative readout

The relative-from-now field is useful for sanity-checking that a timestamp is recent, not stuck in 1970

Built for trust

Privacy & security

This timestamp converter runs entirely in your web browser using date-fns and IANA timezone data. Inputs are never uploaded to any server, stored anywhere, or transmitted. All conversion happens locally on your device.

Frequently Asked Questions

What is a Unix timestamp?

A Unix timestamp is the number of seconds since 1970-01-01 00:00:00 UTC. It is a compact, timezone-free way to represent a specific moment that databases and APIs commonly use.

How does the converter tell seconds from milliseconds apart?

It uses the digit count. 13-digit values are treated as milliseconds and 10-digit and shorter values as seconds. This matches the convention used by JavaScript Date and most Unix systems.

What input formats are supported?

Unix seconds, Unix milliseconds, ISO 8601 strings, RFC 2822 strings, and any string that JavaScript Date can parse including locale-specific formats.

How are timezones handled?

The display timezone selector uses IANA zone names which include daylight saving rules. The same instant is shown converted into the chosen zone.

Is my data sent to any server?

No. Conversion runs entirely in your browser. Inputs are never uploaded, stored, or transmitted to any server.

Why might my date show as 1970 or invalid?

A 1970 result usually means you mixed up seconds and milliseconds, or the input was empty. An invalid result means the string did not match any recognized format. Try a Unix timestamp or ISO 8601 string.