Unix Timestamp to Date Converter
To convert a Unix timestamp to a human-readable date, multiply by 1000 (if seconds) and pass to new Date(), or evaluate datetime.fromtimestamp() in Python. This tool auto-detects seconds vs. milliseconds vs. microseconds vs. nanoseconds, emits ISO 8601, RFC 2822 and timezone-aware variants, and never blocks on a network call.
Quick Conversion
Formula: ms = seconds × 1000
Famous timestamps
Reference table — common timestamps
| Epoch (sec) | ISO 8601 | Weekday (UTC) |
|---|---|---|
| 0 | 1970-01-01T00:00:00.000Z | Thursday |
| 86400 | 1970-01-02T00:00:00.000Z | Friday |
| 31557600 | 1971-01-01T06:00:00.000Z | Friday |
| 946684800 | 2000-01-01T00:00:00.000Z | Saturday |
| 1234567890 | 2009-02-13T23:31:30.000Z | Friday |
| 1577836800 | 2020-01-01T00:00:00.000Z | Wednesday |
| 1700000000 | 2023-11-14T22:13:20.000Z | Tuesday |
| 1717030800 | 2024-05-30T01:00:00.000Z | Thursday |
| 1893456000 | 2030-01-01T00:00:00.000Z | Tuesday |
| 2147483647 | 2038-01-19T03:14:07.000Z | Tuesday |
Need the reverse? Date → timestamp converter.
Formula
date = epoch_seconds × 1000 ms · new Date(ms) · toISOString()Worked: 1717030800 × 1000 = 1717030800000 ms → 2024-05-30T01:00:00.000Z (Thursday).
How to convert a Unix timestamp to a human date
- 1Paste the raw integer into the Timestamp field — the tool will auto-pick seconds, ms, µs or ns based on digit count.
- 2Adjust the unit pill if the auto-detection guessed wrong (e.g. you have a high-precision ms value with only 12 digits).
- 3Read the ISO 8601 line — that's the canonical, sortable UTC form used by databases and JSON APIs.
- 4Scroll the timezone-aware grid to see the same instant rendered in eight common IANA zones (UTC, NYC, LA, London, Berlin, Tokyo, Sydney, Mumbai).
- 5Click Save snapshot to drop the conversion into your local history (no server roundtrip, all in your browser).
Why this calculator exists — and a brief history of epoch time
In 2026 a backend engineer debugging a Snowflake audit log needs to translate a 13-digit EVENT_TS_UTC column into something a product manager can read in the bug report. Switching between seconds and milliseconds by hand burns ten seconds, and Slack's auto-link previewer can't do it. This converter does, in zero round-trips.
Unix time was born on 1970-01-01T00:00:00Z when Ken Thompson and Dennis Ritchie picked an arbitrary "epoch" for the freshly minted PDP-7 UNIX system. The original 1971 manual stored time in sixtieths of a second — that counter overflowed after 2.5 years, so by 1972 it had been replaced with the one-second resolution we know today, codified later in POSIX.1-1990 and refined in POSIX.1-2017.
The ISO 8601 standard (first published 1988, latest revision ISO 8601-1:2019) defined the canonical representation YYYY-MM-DDTHH:mm:ss.sssZ that every modern API speaks. In 2002 Graham Klyne and Chris Newman published RFC 3339, a profile of ISO 8601 hardened for internet protocols — and it's the format you should emit from any JSON endpoint.
Email used a different convention. RFC 822 (1982), revised as RFC 2822 (2001), specified Thu, 30 May 2024 01:00:00 +0000 — verbose, but unambiguous and still alive in every HTTP Date: header your browser sends.
The 2038 problem looms: a signed 32-bit Unix counter overflows on 2038-01-19T03:14:07Z. Linux glibc 2.32 (2020) shipped a 64-bit time_t on 32-bit ARM; macOS, FreeBSD and Windows already had 64-bit time. Embedded firmware — Sonos speakers, supermarket scanners, industrial PLCs — still needs auditing.
On the other side of the cliff: Windows FILETIME, introduced with Windows NT 3.1 (1993), counts 100-nanosecond ticks from 1601-01-01T00:00:00Z. .NET DateTime.Ticks counts from 0001-01-01. Java Instant.toEpochMilli() uses Unix ms. Mac OS Classic counted from 1904-01-01. Our universal epoch converter bridges all of them.
The deeper lesson: timestamps are absolute, timezones are presentation. Store UTC, convert at the edge. This tool was built to make that one-line task instant for anyone debugging a log line at 2 AM.
Trusted by backend engineers, SREs, DBAs and data analysts
“Drop a 13-digit epoch into the box and it instantly tells me UTC, IST and the RFC 3339 form. Faster than any browser extension I've tried.”
“I keep this tab open next to my logs viewer. Auto-detecting sec vs ms vs µs saved me an embarrassing post-mortem moment.”
“Our audit table stores epoch_us. The microsecond branch on this converter is exactly what I needed — no other tool handles it cleanly.”
“Pasting a Snowflake EVENT_TS_UTC column and seeing both ISO 8601 and JST side-by-side is a daily workflow now.”
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