Overview
Computers count time differently from people. Instead of years, months and days, most systems store a single number: the seconds elapsed since midnight on 1 January 1970, UTC. That number is the Unix timestamp, and it turns up everywhere — in databases, APIs, log files, file metadata and JSON payloads. This converter translates it both ways: timestamp to readable date, readable date to timestamp.
You get the answer three ways — UTC, your local time and ISO 8601 — because timezone confusion is the number-one source of timestamp bugs. A live “now” readout ticks underneath for quick reference.
Why 1 January 1970?
Because the engineers building Unix in the early 1970s needed a simple epoch — a zero point — and picked a recent round date in UTC. Storing time as a single incrementing integer made date arithmetic trivial: no months of uneven length, no leap years to handle in the common case. The convention stuck, and today it underpins POSIX systems, most programming languages' time libraries, and countless APIs.
The famous wrinkle is the Year 2038 problem: a signed 32-bit integer overflows on 19 January 2038. Modern systems use 64-bit integers, pushing the overflow billions of years out — but embedded devices and old file formats still carry the 32-bit limit, which is why the converter handles the full range gracefully.
Features
- Both directions: timestamp → date and date → timestamp on one page.
- UTC, local and ISO 8601 shown together to kill timezone confusion.
- Seconds or milliseconds toggle for JavaScript-style 13-digit timestamps.
- Live “now” readout ticking every second for quick reference.
- One-click “use current time” to fill either direction instantly.
- Copy result and fully private local computation.
Benefits
- Read the unreadable. Turn 1792310400 into a date in one paste.
- Debug timezone bugs. UTC and local side by side expose the offset instantly.
- No mental epoch math. Millisecond timestamps handled with a checkbox.
- Works offline once loaded.
Who can use it
Developers debugging APIs and logs, data analysts decoding exported timestamps, QA engineers writing time-based tests, system administrators reading file metadata, and students learning how computers represent time. Anyone who has stared at a 10-digit number in a JSON response and wondered when that was.
How to use
- Choose the direction: Timestamp → Date or Date → Timestamp.
- For timestamp → date: paste the number; tick “milliseconds” if it has 13 digits.
- For date → timestamp: pick the date and time (interpreted in your local zone).
- Read the UTC, local and ISO 8601 equivalents underneath.
- Use “Use current time” or the live readout when you need right-now values.
Frequently asked questions
Is my timestamp in seconds or milliseconds?
Count the digits: 10 digits means seconds (e.g. 1792310400), 13 means milliseconds (e.g. 1792310400000). JavaScript's Date.now() returns milliseconds; most APIs and databases use seconds. The checkbox converts between the two — a wrong guess shows a date in 1970 or the year 56000, which is your clue.
Why does the same timestamp show two different times?
Because of timezones. The timestamp itself is timezone-free — it counts seconds since the UTC epoch. Your local display adds your zone offset (and daylight saving). UTC never shifts, which is why servers log in UTC and convert only for display.
What is the 2038 problem?
On systems storing timestamps as signed 32-bit integers, the counter overflows on 19 January 2038 and wraps to 1901. Modern 64-bit systems are immune for billions of years, but 32-bit embedded devices and legacy formats still need attention — much like Y2K, it rewards early checking.
Do leap seconds break Unix time?
Unix time pretends they do not exist: every day is exactly 86,400 seconds, and leap seconds are smeared or skipped depending on the system. For most applications this is fine; for astronomy and high-frequency trading, specialised time scales handle it properly.
Is anything I convert uploaded?
No. Conversion is pure date arithmetic in your browser — timestamps and dates never leave the page.
Conclusion
One number, three readings, zero timezone tears. Paste the timestamp, read the date — and when a log says 1792310400, you will know exactly when that was.