Unix Time Converter
Convert any Unix timestamp to a readable date and time across every time zone. Originated at Bell Labs in New Jersey — the birthplace of Unix.
What Is Unix Time?
Unix time is the number of seconds elapsed since 00:00:00 UTC on January 1, 1970. It was created at Bell Labs in Murray Hill, New Jersey — the same lab that gave the world the transistor, C language, and Unix itself.
Today Unix timestamps power everything from POSIX-compliant operating systems to REST APIs and real-time financial feeds on Wall Street.
Conversion Formulas
Other timestamp units are powers-of-ten multiples of the base second value. Converting to local time shifts by the UTC offset.
Unit conversions
t_ms = t_sec × 10^3 t_ s = t_sec × 10^6 t_ns = t_sec × 10^9tms=tsec×103tμs=tsec×106tns=tsec×109
Converting to local time
t_local = t_epoch + Δ_UTC × 3600tlocal=tepoch+ΔUTC×3600
Where Δ_UTC is the offset in hours (e.g. −5 for EST, −8 for PST). DST entries show fixed offsets — actual transitions depend on region and year.
Real-World Examples
Bell Labs Origin
Unix time was conceived around 1969 at Bell Labs, NJ. The epoch (timestamp 0) = 1970-01-01 00:00:00 UTC = 1969-12-31 07:00 PM EST — it was still New Year's Eve in New York.
Y2K38 on US Infrastructure
Embedded systems in US power grids, water treatment plants, and older SCADA systems that store time as 32-bit integers will overflow on 2038-01-19 at 03:14:07 UTC (10:14 PM EST the night before).
NYSE/NASDAQ Nanosecond Timestamps
US financial regulations (FINRA, SEC Rule 613) require equity trade timestamps accurate to at least 1 millisecond. High-frequency trading firms in New York use nanosecond-precision Unix clocks.
REST API Rate-Limit Headers
Most US-based API platforms (GitHub, Stripe, Twilio) return rate-limit reset times as Unix timestamps in the X-RateLimit-Reset HTTP header — always in seconds.
How to Use This Converter
1
Type a Unix timestamp into the input field, or click "Use current time" to load the current epoch second.
2
Select the unit that matches your timestamp: seconds, milliseconds, microseconds, or nanoseconds.
3
The reference time box shows your timestamp expressed in all four units simultaneously.
4
Scroll through the five timezone groups to find any US time zone (EST, CST, MST, PST, AKST, HST) and read the local date and time.
5
Copy any value by selecting the text in the table cell.
Tips & Common Pitfalls
- ✦Python, Go, and Rust default to seconds. JavaScript, Java, and most mobile SDKs return milliseconds — watch for 13-digit timestamps.
- ✦Timestamp 0 is not null or missing — it means January 1, 1970 00:00:00 UTC exactly.
- ✦DST offsets in the table are fixed. Actual US DST transitions (second Sunday in March / first Sunday in November) are not reflected here.
- ✦Negative timestamps represent dates before 1970 — −1 = December 31, 1969 23:59:59 UTC.
- ✦Always confirm whether a timestamp from an external API is in seconds or milliseconds before arithmetic.
Frequently Asked Questions
Why does Unix time start on January 1, 1970?
Bell Labs engineers chose a round date that was recent during development (1969–71). The midnight UTC boundary made integer arithmetic simple.
What is the Y2038 problem?
32-bit signed integers overflow at 2,147,483,647 — corresponding to 2038-01-19 03:14:07 UTC. All modern 64-bit systems extend the range by hundreds of billions of years.
How do I convert a Unix timestamp in JavaScript?
Use new Date(timestamp * 1000) for seconds, or new Date(timestamp) for milliseconds. Date.now() always returns milliseconds.
Does Unix time handle leap seconds?
No. Each day is treated as exactly 86,400 seconds. Leap seconds are smeared, so Unix time and UTC can differ by a few seconds.
How do I get a Unix timestamp in Python?
Use time.time() for a float, int(time.time()) for an integer, or datetime_obj.timestamp() for a datetime object.
What is the difference between UTC and GMT?
Practically the same offset. GMT is the historical meridian-based zone; UTC is the atomic-clock standard used in computing.