Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates, in your local time zone.

Current Unix timestamp

UTC

Timestamp → Date

Date → Timestamp

What Is the Unix Timestamp Converter?

This tool converts between Unix timestamps (seconds or milliseconds since January 1, 1970 UTC) and human-readable dates in both your local time zone and UTC.

How Is the Unix Timestamp Converter Calculated?

A Unix timestamp counts the number of seconds (or milliseconds) that have elapsed since the Unix epoch — midnight UTC on January 1, 1970. Converting to a readable date applies your browser's local time zone offset to that count; converting back subtracts the same offset before counting elapsed seconds from the epoch.

Unix Timestamp Converter Example

The timestamp 1735689600 corresponds to January 1, 2025, 00:00:00 UTC.

How to Use the Unix Timestamp Converter

Step 1

To convert a timestamp to a date, paste it into the Timestamp field and choose seconds or milliseconds.

Step 2

To convert a date to a timestamp, pick a date and time in the Date field.

Step 3

Use "Use current time" to fill in right now's timestamp.

Step 4

Copy any result — local time, UTC, ISO 8601, seconds, or milliseconds.

Benefits

  • Shows local time, UTC, and ISO 8601 all at once, so you don't need a separate time zone conversion step.
  • Supports both seconds and milliseconds, the two most common timestamp formats used in APIs and databases.
  • Displays a live-updating current timestamp for quick reference.

Common Unix Timestamp Converter Scenarios

Scenario 1

Debugging an API response or database field that stores dates as Unix timestamps.

Scenario 2

Converting a log file timestamp into a readable local date and time.

Scenario 3

Getting the exact timestamp for scheduling a future event in code.

Understanding Your Result

The Local time reflects your browser's detected time zone (shown above), while UTC and ISO 8601 are time-zone-independent — use UTC or ISO 8601 when sharing a timestamp with someone in a different time zone to avoid ambiguity.

Tips

  • JavaScript's Date.now() and most JSON APIs use milliseconds, while many Unix/Linux tools and databases use seconds — double-check which one you need.
  • ISO 8601 format (like 2025-01-01T00:00:00.000Z) is the least ambiguous way to store or share a timestamp across systems.
  • If a timestamp looks 1000x too large or too small, you likely have the seconds/milliseconds unit swapped.

Common Mistakes

  • Mixing up seconds and milliseconds, which produces a date far in the past or far in the future.
  • Assuming a Unix timestamp already reflects a specific time zone — it's always a UTC-based count, and local time is only a display convenience.
  • Forgetting that Unix timestamps are typically limited to dates after 1970 in most practical implementations.

Frequently Asked Questions

Does this tool send my timestamp or date data anywhere?

No, all conversion happens locally in your browser using standard JavaScript Date functions — nothing is sent to a server.

What time zone is 'Local' based on?

It's based on your browser's detected system time zone, shown above the current timestamp.

Why do seconds and milliseconds give different-looking numbers for the same moment?

A millisecond timestamp is exactly 1000 times larger than the equivalent seconds timestamp for the same instant.

Can this handle dates before 1970?

Yes, negative Unix timestamps represent dates before January 1, 1970, and this tool will convert them correctly.

Why does Unix time start at January 1, 1970?

That date was chosen as an arbitrary but convenient reference point (called the 'Unix epoch') when the Unix operating system was being developed, and it has remained the standard reference point ever since.

Can Unix timestamps represent dates before 1970?

Yes — using a negative timestamp value represents a date before the 1970 epoch, and most modern systems handle negative Unix timestamps correctly.

Why do some systems use seconds and others use milliseconds for Unix time?

It depends on the required precision — many programming languages and databases traditionally use seconds, while JavaScript's built-in Date object uses milliseconds since the epoch for finer time granularity.

Will Unix timestamps eventually run out or overflow?

Systems using a 32-bit signed integer for Unix time will overflow in the year 2038 (known as the 'Year 2038 problem'), though most modern systems now use 64-bit integers, which won't overflow for billions of years.

How do I convert a Unix timestamp to my local time zone manually?

Unix timestamps represent a moment in UTC; converting to local time requires adding or subtracting your time zone's offset from UTC, which is exactly what this tool automates for you.

Important Information

All conversions happen locally in your browser using your system clock and time zone.

Last updated: July 27, 2026