Start Submit a site

Unix Timestamp Converter

Developer Tools

Convert a Unix timestamp into UTC and local time, or turn any date and time back into seconds and milliseconds.

Your inputs

Browse all tools

Result

Unix timestamp (seconds) —
  • Milliseconds —
  • ISO 8601 (UTC) —
  • UTC time —
  • Local time —
  • Relative to now —

Change any input and the result updates instantly.

Formula and rules

  • Unix time counts the seconds since 1 January 1970 00:00:00 UTC, ignoring leap seconds.
  • Milliseconds = seconds × 1000, which is why JavaScript Date values are 13 digits long.
  • Values of 1×10¹¹ or more are treated as milliseconds when automatic detection is on.
  • Local time uses the time zone reported by your browser, so it changes with daylight saving.

Worked examples

Epoch zero

Input Timestamp 0, seconds.

Result 1970-01-01T00:00:00.000Z — the Unix epoch.

Start of 2026

Input Timestamp 1767225600, seconds.

Result 2026-01-01T00:00:00.000Z, or 1767225600000 in milliseconds.

Date back to timestamp

Input 2026-10-24 09:30 in the browser time zone.

Result Epoch seconds shift by the UTC offset, so the same wall-clock time gives different timestamps in different zones.

FAQ

Is a Unix timestamp in seconds or milliseconds?

Classic Unix time is seconds. JavaScript, Java and many APIs use milliseconds, which look like 13-digit numbers. This tool lets you force either unit or detect it from the length.

Why does my local time differ from UTC?

UTC never shifts, while local time adds your time zone offset, including daylight saving. A timestamp is an absolute instant, so only its display changes.

What happens after 2038?

The 2038 problem affects 32-bit systems that store seconds in a signed integer. This converter uses JavaScript numbers, which handle dates far beyond 2038.

Related calculators

JSON to YAML Converter Paste JSON and get clean YAML instantly — pick 2 or 4 space indent, keep the original key order or sort keys, all inside your browser. Base64 Encoder and Decoder Encode text to Base64 or decode it back, with UTF-8 support and an optional URL-safe alphabet — nothing leaves your browser. Aspect Ratio Calculator Resize a video, image or canvas to any aspect ratio and get the missing width or height plus the megapixel count. Data Storage Converter Convert between bits and bytes, KB, MB, GB and TB in both decimal (1000) and binary (1024) units. Candle Wax Calculator Work out exactly how much wax and fragrance oil a jar, tin or mold needs — in grams and ounces. Image Compressor Shrink JPG, PNG and WebP photos in your browser — pick a quality level and a max size, then download the smaller file. Nothing is uploaded.

More in this category: JSON to YAML Converter Base64 Encoder and Decoder Aspect Ratio Calculator Data Storage Converter JSON Formatter, Validator and Minifier JWT Decoder MD5, SHA-1 and SHA-256 Hash Generator URL Encoder and Decoder

Disclaimer: Results follow the formula shown on this page and are for reference only. Real-world quantities vary with materials, technique and conditions, so allow a margin before ordering.