# Unix timestamp converter

URL: https://www.toolflux.app/en/unix-timestamp-converter/
Stand: 2026-05-06

Unix timestamp converter with 16 readings: Unix, ISO 8601 and 12 calendar/date notations - Julian Day, Mayan, Hijri, Thai Buddhist, Ethiopian, Indian Saka and more. Y2038 warning. Local in your browser.

An instant is always the same instant - the name for it depends on the system. The converter below renders your moment in sixteen notations at once: Unix seconds for machines, ISO 8601 for JSON, Julian Day for astronomers, Mayan Long Count for history threads, Hijri / Thai / Ethiopian / Saka for national and religious contexts. Plus a Y2038 banner when your value crosses the 32-bit boundary.

## Three notations for machines, one for humans

The top "machine-readable" group has the three readings that drop straight into code:

- **Unix seconds.** The POSIX standard. `time(NULL)` in C, `Time.now.to_i` in Ruby. A number like 1746576000.
- **Unix milliseconds.** JavaScript native (`Date.now()`), Java (`System.currentTimeMillis()`), many newer APIs. Three digits longer than seconds.
- **ISO 8601 / RFC 3339.** The human-and-machine standard. `2026-05-07T13:45:00+02:00` in your selected timezone, or `2026-05-07T11:45:00Z` when UTC is selected. The right call in JSON - unambiguous because of the offset.

Just below, in the "human-readable" group, sits **UTC and local**: UTC rendered unambiguously plus the local time with weekday, DST marker, and ISO week number - the card you forward to a colleague.

If you only remember one notation: ISO 8601 with explicit offset. Unambiguous, sortable, understood everywhere.

## Niche cards for context

The lower cards are specialist readings:

- **Relative.** "3 days ago", "in 5 hours". Handy for UI, bad for logs (no anchor).

First the calendars still in official or civic use today:

- **Japanese era.** Reiwa since May 2019. Official notation in Japan alongside Gregorian.
- **Chinese.** Lunisolar with a 60-year stem-branch cycle. From Chinese New Year on 17 February 2026 the year is 丙午 (bing-wu, "Fire Horse"); the first six weeks of 2026 are still 乙巳 (Wood Snake).
- **Islamic (Hijri).** Pure lunar, about 11 days shorter than the solar year. Currently around 1447 AH.
- **Thai Buddhist Era.** Thailand's official dating. Same months as Gregorian; the year is 543 higher: 2026 = 2569 BE. Printed on every Thai national ID card and in the Royal Gazette.
- **Indian National (Saka).** India's official calendar, introduced 22 March 1957 by the Calendar Reform Committee under Meghnad Saha. The Gazette of India and All India Radio carry it alongside Gregorian. The year starts on 1 Chaitra (22 March, or 21 March in leap years); from that day Saka = Gregorian − 78, and before it − 79.
- **Ethiopian.** Civil calendar of Ethiopia, used informally in Eritrea. Twelve 30-day months plus Pagumē of 5 or 6 days. Sits about 7 years 8 months behind Gregorian; New Year (Enkutatash) falls on 11 September (12 September the year before a Gregorian leap year).

Then the historical and specialist notations:

- **Julian Day Number.** Continuous day counter since 4713 BC. Astronomers use it because the gap between two JDNs is a simple subtraction - no month boundaries.
- **Mayan Long Count.** Five places, baktun.katun.tun.uinal.kin. The famous 13.0.0.0.0 rollover was 21 December 2012. Today (2026) we're at 13.0.13.x.x.
- **French Republican.** The revolutionary calendar 1793-1805. Twelve 30-day months plus 5 or 6 sansculottide days at year-end. Surfaces in French history threads.

## Y2038 - the 32-bit overflow

On 19 January 2038 at 03:14:07 UTC, a signed 32-bit Unix timestamp hits its maximum value. The next second wraps - many old systems suddenly read 13 December 1901. The converter shows a red warning when your input is past that date.

Who's affected: 32-bit embedded systems, old industrial PLCs, some database schemas with `INT(11)` for timestamps, older C codebases without `time64_t`. Who isn't: 64-bit Linux/macOS/Windows, modern JavaScript engines, Postgres / MySQL with `BIGINT`. The browser itself is 64-bit and renders the value fine.

Building today against dates after 2038 (pensions, insurance, long-term contracts): use 64-bit timestamps or ISO 8601 strings, never 32-bit Unix seconds.

## DST marker

Under the input field, the converter shows the next DST transition for the selected timezone. Example: Europe/Berlin switches in 2026 on 25 October (last Sunday) from summer to standard time. Useful for avoiding cron double-runs or meeting collisions.

The European Parliament voted in 2019 to end DST changes. The Council of the EU has not adopted a common position since, so the proposal has stalled. For now the transitions remain.

## "Now" button and live mode

Click "Set to now" - the current browser instant loads and the cards animate as they light up, a 1-second self-demo of the tool's full surface. Afterwards the converter runs in live mode: values update each second. As soon as you type in the input field, live mode pauses and you see the typed instant statically.

## Timezone selector

By default the converter uses your browser timezone. The dropdown switches to common zones: UTC, Europe/Berlin, Europe/London, America/New_York, Asia/Tokyo, etc. The ISO card then writes the same instant with the offset of the selected zone (`+02:00`, `-07:00`, etc.) - switch to UTC and it collapses to `…Z`.

Important: Unix seconds, Unix milliseconds, Relative, Julian Day, Mayan Long Count, French Republican, stardate, and Discordian are timezone-independent - they count the same absolute instant. Switching the timezone changes the local part of the UTC-and-local card, the offset on the ISO card, and any calendar card whose date can roll over midnight in a different zone (Japanese era, Hijri, Chinese, Thai, Saka, Ethiopian).

## FAQ

### What is a Unix timestamp and how do I convert it?

A Unix timestamp is the number of seconds since 1 January 1970 00:00:00 UTC. In the converter above, type the value - it auto-detects seconds, milliseconds, microseconds, or nanoseconds.

### What's the difference between Unix seconds and milliseconds?

Seconds: 1746576000. Milliseconds: 1746576000000. JavaScript uses ms (Date.now), C/POSIX uses s (time()).

### When does a 32-bit Unix timestamp overflow (Y2038)?

19 January 2038 at 03:14:07 UTC. 64-bit systems are unaffected; 32-bit legacy systems flip.

### What does today's Mayan Long Count look like?

Today around 13.0.13.x.x. The 13.0.0.0.0 rollover was 21 December 2012.

### FAQ

**What is a Unix timestamp and how do I convert it?**

A Unix timestamp is the number of seconds since 1 January 1970 00:00:00 UTC. A typical 2026 value is around 1.7 billion. In the converter above just type the value - it auto-detects whether it's seconds, milliseconds, microseconds, or nanoseconds and renders all 16 readings.

**What's the difference between Unix seconds and milliseconds?**

Unix seconds is the classic POSIX form: a value like 1746576000. Milliseconds is three digits longer: 1746576000000. JavaScript uses milliseconds (Date.now), databases and APIs often use seconds. Higher resolutions exist: BigQuery stores TIMESTAMP internally as microseconds (UNIX_MICROS), InfluxDB defaults to nanoseconds.

**When does a 32-bit Unix timestamp overflow (Y2038)?**

On 19 January 2038 at 03:14:07 UTC, a signed 32-bit Unix timestamp hits its maximum (2³¹ - 1). One second later it wraps to -2³¹, which the system interprets as 13 December 1901. Modern 64-bit systems aren't affected. Legacy software, embedded devices, and old databases can break at that date. The converter shows a red Y2038 warning when the input crosses that boundary.

**What is the Julian Day Number?**

Julian Day Number (JDN) is a continuous day counter starting on 1 January 4713 BC, noon UT. Astronomers and historians use it because it has no month boundaries - the gap between two dates is just the difference of their JDNs. Example: 1 January 2000 is JDN 2451545 (the J2000.0 astronomy epoch).

**What does today's Mayan Long Count look like?**

The Mayan Long Count uses five places: Baktun.Katun.Tun.Uinal.Kin (144000 / 7200 / 360 / 20 / 1 days each). The famous 13th-baktun rollover (13.0.0.0.0) was 21 December 2012 - not the end of the world but a transition. Today (2026) we're at 13.0.13.x.x. The converter uses the academically accepted GMT correlation 584283; other correlations shift the date by a few days.

**When does daylight saving time end?**

In Europe/Berlin, DST ends each year on the last Sunday of October (e.g. 26 Oct 2025) at 03:00 local time, falling back to 02:00. DST starts on the last Sunday of March. The converter shows the next DST transition for the selected timezone under the input field. Tip: ISO 8601 with offset (e.g. 2026-05-07T13:45:00+02:00) is unambiguous - you don't need to guess summer or winter time.

**Which timezone notation is unambiguous in JSON?**

ISO 8601 with an explicit offset or UTC Z. 2026-05-07T13:45:00+02:00 or 2026-05-07T11:45:00Z are unambiguous. Avoid bare 'YYYY-MM-DD HH:MM:SS' strings without timezone info - APIs and consumers will guess locally, leading to DST bugs. The ISO card in the converter is JSON-ready.