Developer/Unix Timestamp Converter

Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates. 100% local.

100% LOCALSec/msISO 8601Timezone awareOne-click now
Timestamp → Date
2025-01-01T00:00:00.000Z
UTC: 2025-01-01 00:00:00
Weekday: Wednesday
Date → Timestamp
1780747200 (s)
Data Source & Legal Disclaimer
Effective: 2026
Sources: Browser-side processing (no external API)

This tool runs 100% in your browser. All computation happens locally on your device — your input is never uploaded to any server. Results are for reference only.

See all data sources & update policy →

What a Unix timestamp is — illustrated

A Unix timestamp counts the seconds elapsed since 1970-01-01 00:00:00 UTC (the "epoch"). Any instant in time collapses to a single integer, which is why computers love it.

Epoch → elapsed seconds → human date
EPOCH1970-01-01 UTC1975200020261780000000 ssplits into →yrmodayhrminsec

Top: time is a single integer counting from the epoch. Bottom: that integer is split back into year / month / day / hour / minute / second in UTC. Milliseconds timestamps simply count 1,000 per second.

Known anchors to check yourself

Every computer agrees on these — paste them in and compare with your local timezone.

  1. Epoch 0:1970-01-01 00:00:00 UTC
  2. 1,700,000,000 s:2023-11-14 22:13:20 UTC
  3. Now button:Fills the current second since the epoch
↩ Back to converter

To convert a timestamp: enter a Unix timestamp (seconds or milliseconds) or a date — the tool instantly converts between formats with timezone support.

FreeToolHub Unix Timestamp Converter is a free browser-based tool that converts between Unix timestamps and human-readable dates, no signup.

About this tool

What is this tool?

Convert between Unix timestamps and human-readable dates. Supports seconds, milliseconds, UTC, and local timezones. Free, no signup.

Sec/msISO 8601Timezone awareOne-click now

What Is the Unix Timestamp Converter?

This converter translates between Unix timestamps — the integer seconds or milliseconds since January 1, 1970 UTC — and human-readable dates. Paste 1767225600 and instantly see the full date in UTC and your local timezone; type a date and get the timestamp back in both precisions. It handles the two unit systems that cause real bugs, seconds versus milliseconds, detecting or letting you specify which you mean, and renders relative context like how long ago a timestamp was. Everything converts locally, which matters when logs contain internal system identifiers.

Who Should Use This Tool?

Backend developers read API responses, database rows, and JWT claims whose dates arrive as raw numbers. Debuggers reconciling log timestamps across server timezones determine whether an event happened before or after another despite formatting differences. Data analysts convert spreadsheet epoch columns into readable dates before reporting. Anyone configuring cache expiry, token lifetimes, or scheduled jobs sanity-checks that the number they are about to hardcode means the date they think. Students learning systems programming get instant intuition for the epoch scale.

How Does It Work?

(1) Paste a timestamp — the tool auto-detects seconds versus milliseconds by magnitude (10-digit values are seconds, 13-digit are milliseconds) and converts both ways. (2) The readable date renders in UTC and local time side by side, with day-of-week for scheduling context. (3) In reverse, pick any date and time to get epoch values in both units. (4) The now button captures the current timestamp for copy-paste into configs and queries. Negative values before 1970 work too, and conversions handle leap seconds the same way most systems do: by ignoring them.

Why Do Seconds vs Milliseconds Timestamps Break Things?

The Unix ecosystem never fully standardized precision: C and databases traditionally count seconds, while JavaScript's Date.now() and Java's System.currentTimeMillis() count milliseconds. Consequences surface constantly — a millisecond timestamp pasted into a seconds-expecting system lands thousands of years in the future, and the reverse produces 1970s dates; both are classic production bugs in mixed stacks. JavaScript's choice also explains JSON dates: APIs returning milliseconds since epoch come from JS backends. The magnitude rule makes detection trivial: seconds timestamps are 10 digits until the year 2286; milliseconds are 13. When integrating systems, normalize to one precision at the boundary, store UTC always, and convert to local time only at display — the discipline that eliminates an entire class of timezone defects.

Frequently Asked Questions

What is a Unix timestamp and why is it used?

A Unix timestamp is the number of seconds since January 1, 1970 UTC (the Unix epoch). It is timezone-independent, making it ideal for databases, APIs, and logging systems. This tool converts between Unix timestamps (seconds or milliseconds) and human-readable dates in UTC and your local timezone.

How do I convert a Unix timestamp in JavaScript or Python?

In JavaScript: new Date(timestamp * 1000) for seconds, or new Date(timestamp) for milliseconds. In Python: datetime.datetime.fromtimestamp(timestamp). This tool handles both seconds and milliseconds automatically, and displays the result in multiple timezone formats simultaneously.

Other names for this tool

This tool is also known by these tasks — each link opens the same tool with a focused guide:

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