Unix Timestamp Converter

Convert Unix timestamps (seconds or milliseconds) to local or UTC dates and back. Auto-detects units, shows ISO 8601 and RFC 2822. Applies time offsets.

Now

Convert Unix → Date

Convert Date → Unix

Common Timestamps

Today 00:00 local

Today 00:00 UTC

Tomorrow 00:00 local

Next Monday 00:00

How it works

Type any timestamp — the tool auto-detects seconds (10 digits) or milliseconds (13 digits). You can paste from logs, JSON, or HTTP headers.
Every conversion shows local time, UTC time, ISO 8601, and RFC 2822 — the formats developers need across languages and APIs.
The Common Timestamps section gives you one-click values for daily batch jobs, cron schedules, and event planning.

Seconds, milliseconds and the ambiguity

Unix time is seconds since 1970-01-01 UTC. JavaScript's Date uses milliseconds, which is the single most common source of wrong dates when values cross a language boundary: a millisecond value interpreted as seconds lands in the year 56000-something, and a second value read as milliseconds lands in January 1970.

This tool auto-detects which unit a value uses and shows the result in local time, UTC and ISO 8601 so you can confirm which reading was correct.

Time zones and daylight saving

ISO 8601 strings carry an offset (`Z` means UTC, `+02:00` is a fixed offset). Naive strings carry neither, and interpreting one requires knowing which zone it was meant in — the assumption that it is UTC is a frequent cause of an off-by-hours bug in a scheduled job.

Frequently Asked Questions

How do I convert between Unix timestamps and dates?

Enter a Unix timestamp (seconds or milliseconds) or a date/time string and the tool instantly shows the conversion in all major formats: Unix, ISO 8601, UTC, local time, and over 20 timezone-specific formats.

Can I convert timestamps in bulk?

Yes. Enter multiple timestamps (one per line) and the tool converts all of them simultaneously, displaying results in a table with all format columns.

Is my data sent to a server?

No. Every tool on jsonversal runs entirely in your browser using the Web Crypto API, File API, and Clipboard API. Nothing is ever uploaded — not even the JSON you paste in.

Do I need an account or API key?

No signup, no email, no API key. All tools are free to use with no signup required.

Can I use these tools offline?

Yes. Once the page loads, all tools work offline. There are no external API calls or CDN dependencies at runtime.

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Your data never leaves your device

All processing happens in your browser. No uploads, no tracking, no servers. Your API keys, configs, and private payloads stay private — 100% client-side.