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

In JavaScript, run: new Date(timestamp * 1000).toISOString(). In Python, run: datetime.datetime.fromtimestamp(timestamp, tz=datetime.timezone.utc).

Does Unix time include leap seconds?

POSIX standards specify that each day contains exactly 86,400 seconds. When a leap second is inserted, the Unix second counter repeats or smears the final second, keeping it closely aligned with UTC.

What is the Year 2038 Unix timestamp problem?

The Year 2038 problem (Y2038) refers to 32-bit signed integers overflowing when Unix time reaches 2,147,483,647 seconds on January 19, 2038 at 03:14:07 UTC. Modern 64-bit operating systems resolve this by supporting timestamps well beyond 292 billion years.

How to convert Unix timestamp seconds to readable human date in JavaScript?

In JavaScript: const date = new Date(timestamp * 1000); console.log(date.toISOString()); For milliseconds: const date = new Date(timestampMs).

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

In JavaScript, run: new Date(timestamp * 1000).toISOString(). In Python, run: datetime.datetime.fromtimestamp(timestamp, tz=datetime.timezone.utc).

Does Unix time include leap seconds?

POSIX standards specify that each day contains exactly 86,400 seconds. When a leap second is inserted, the Unix second counter repeats or smears the final second, keeping it closely aligned with UTC.

Developer Tools Suite

Unix Epoch Timestamp Converter

Live atomic epoch in seconds & milliseconds, bidirectional ISO 8601 formatting, and technical documentation.

Epoch Seconds (Live)

1791649413

Epoch Milliseconds (Live)

1791649413200

Convert Timestamp to Readable Human Date

Enter Epoch Seconds or Milliseconds

UTC / GMT Date

Sat, 10 Oct 2026 16:23:33 GMT

ISO 8601 String

2026-10-10T16:23:33.000Z

Local Device Time

10/10/2026, 4:23:33 PM

Relative Time

0 days relative to today

Free Anonymous REST API

View API Docs →

Query real-time timezone, UTC offsets, and atomic epoch data programmatically with 0 auth headers:

curl -s https://www.timenumbers.com/api/v1/time?city=tokyo

Frequently Asked Questions on Unix Epoch & Standards

Common queries, time calculations, and scientific explanations

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Epoch timestamp is the elapsed number of seconds since 00:00:00 UTC on Thursday, January 1, 1970 (not counting leap seconds). UTC (Coordinated Universal Time) is the international atomic time standard. GMT (Greenwich Mean Time) is an observational time zone historically aligned with the Royal Observatory in Greenwich.

Explore Global Time & Related Directories

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Explore Interactive Map

Precision Horology & Global Time Tools

City Time Differences Directory

Exact hours ahead & overlap for 92+ city pairs

Coordinated Universal Time (UTC)

Canonical atomic reference standard and UTC offset zero

Multi-Zone Time Converter Hub

Convert hours across global zones and cities

Compare World Cities

Direct side-by-side time difference and overlap

United States Time Now

Live atomic clocks across all US time zones and Washington D.C.

Exact Time Digital Clock

Precision digital chronometer with seconds and atomic reference

Online Pomodoro Timer

25/5 study and deep work productivity intervals

Accurate Analog Clock

Smooth sweeping second hand and Swiss watch dial

552 Timezone Converters

Visual timeline converter across 552 global timezone pairs

Date Difference Calculator

Exact days, weeks, months & business days between dates

Date Calculator

Add or subtract days, weeks, months & business days

Golden Hour Calculator

Exact photography lighting, blue hour & civil twilight times

Sunrise & Sunset Times Hub

NOAA algorithm solar dawn and dusk times worldwide

Moon Phases & Illumination

Live lunar surface illumination % and 29.5-day synodic cycle

Interactive World Time Map

Real-time solar terminator, day/night zones & 46 live clocks

400+ Time Zones Directory

Complete canonical IANA database with live ticking clocks

Interactive Timezone Map

Live global clock bands with clickable UTC offset zones

World Cities Directory

Current local time and population across global metropolises

Today's Date Details

Day of year, ISO week, Julian day & year progress percentage

ISO Week Number Calculator

Current ISO week number, calendar quarters & weeks remaining

ISO 8601 String Parser

Parse, validate and format ISO-8601 date-time strings

Unix Timestamp Converter

Epoch seconds converter to human readable UTC & local time

Astronomy & Twilight Lab

Sunrise, sunset, golden hour & moon phase calendar

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Country calling codes & smart calling hour guide

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Trading floor kiosk with Swiss analog & digital dials

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Travel time & circadian light adjustment protocol

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Fullscreen bedside display with Web Audio chimes

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Overlap working window across 4+ global hubs

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Mutual working hours matrix for remote teams

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Working days between dates & 90-day deadlines

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Weeks, days & exact chronological age tracker

Atomic Clock Accuracy

NTP drift latency benchmark

Unix Timestamp Studio

Epoch seconds converter & 2038 lab

Military Time Converter & Chart

Convert 12h to 24h military time with spoken pronunciation & printable chart

Work Hours & Timesheet Calculator

Calculate weekly hours, lunch deductions, overtime pay & gross wages

Best Time to Call Calculator

Find overlapping daytime calling window between international cities

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Head-to-head differences (CST vs EST, PST vs MST, GMT vs UTC)

Daylight Saving Schedule

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Horology Learning Academy

Deep dive into UTC, leap seconds & chronometry

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Interactive DA vs Keyword Difficulty ranking simulator

High-Volume City Time Differences

All 92 City Differences Directory →Paris vs New York London vs Tokyo New York vs London New York vs São Paulo New York vs Honolulu Los Angeles vs Honolulu Dubai vs Delhi Tokyo vs Sydney San Francisco vs Paris Compare All Cities Matrix →

Convert Timestamp Seconds and Milliseconds Instantly

Translating between raw integer timestamps and human calendar dates is an everyday task for software engineers, database admins, and DevOps professionals. Our interactive converter accepts 10-digit seconds, 13-digit milliseconds, and microsecond strings, translating them into UTC, local civil time, and ISO 8601 formats.

Need to generate an epoch number from a future launch date? Enter any calendar day and time to extract clean timestamps along with copy-pasteable code snippets for SQL, JavaScript, Python, and Go.

Human-Readable Dates to Epoch Timestamps

10-digit seconds vs 13-digit milliseconds, leap second smearing, and Python/JavaScript/Go snippets.

Developer Code Snippets: Python, JS, Go & SQL

10-digit seconds vs 13-digit milliseconds, leap second smearing, and Python/JavaScript/Go snippets.

Frequently Asked Questions: Unix Timestamps

Common queries, time calculations, and scientific explanations

Google SERP Verified

Standard 10-digit timestamps (e.g., 1774320000) represent seconds. A 13-digit timestamp (e.g., 1774320000000) represents milliseconds, commonly generated by JavaScript's Date.now().