Instant Unix Timestamp Converter & Studio — Fast, Accurate Epoch Conversions (100% Offline)
Convert Unix Epoch timestamps to human-readable dates and vice versa with our 100% offline Unix Epoch Time Converter. Features a live epoch clock and UTC support.
Table of Contents
Staring at a raw Unix timestamp in a log and want the real date behind it? Convert an epoch value into a readable time across different time zones, or turn a calendar date back into its timestamp. It is the quick reference you want open when you are lining log entries up against real-world times.
Epoch & Time Studio - Convert, Compare and Calculate
Turn a Unix timestamp into every format a developer actually meets - ISO 8601, SQL, Excel serial numbers, .NET ticks and Windows FILETIME - then compare that instant across time zones, work out durations and business days, or convert a whole column at once. Runs on your browser's own date engine with nothing downloaded.
Input
From a Timestamp
Or From a Date
Or Paste Any Format
Every Format
Meeting Planner
Zones
Add or Subtract
Difference Between Two Dates
Notes on This Date
Batch Convert
Code Snippets
Last Updated: August 2026
🟢 More Than Epoch In, Date Out
Converting 1753100000 into a readable date takes one line of code. The reason a tool is still useful is everything around that: the log file gives you milliseconds, the spreadsheet wants an Excel serial number, the Windows event log hands you an eighteen-digit FILETIME, and the person waiting for your answer is in a different time zone.
This page does the whole set in one place, and it runs on the date engine already built into your browser – there is no library to download.
| Tab | What it handles |
|---|---|
| Convert | Seconds through nanoseconds, sixteen output formats, relative time, format detection on paste |
| World Clock | One instant across many zones with daylight saving marked, plus a working-hours planner |
| Date Calculator | Add or subtract intervals, differences with business days, and notes on awkward local times |
| Batch & Code | A whole column converted to CSV, and conversion snippets in seven languages |
🟡 The Formats, And Where You Meet Them
Most people arrive knowing epoch seconds and nothing else. These are the others worth recognising, because each one comes from somewhere specific.
| Format | Looks like | Where it comes from |
|---|---|---|
| Epoch seconds | 1753100000 | Unix systems, APIs, most databases |
| Milliseconds | 1753100000000 | JavaScript and Java |
| ISO 8601 | 2026-07-21T14:30:00Z | APIs and data interchange |
| SQL DATETIME | 2026-07-21 14:30:00 | Database columns and query output |
| Excel serial | 46224.60417 | Spreadsheet cells – a day count, not seconds |
| .NET ticks | 639201888000000000 | C# and .NET, counted from year 1 |
| Windows FILETIME | 134290656000000000 | Windows APIs and event logs, counted from 1601 |
| Mac absolute | 806284800 | Apple frameworks, counted from 2001 |
The Paste box handles all of these. It reads the magnitude of the number and decides what it must be – an eighteen-digit value is FILETIME, a five-digit value in the forty-thousands is an Excel serial – so you rarely have to say which one you have.
🔴 The Warning That Saves A Migration
Enter 2147483648 and a red panel appears.
That number is one past the largest value a signed 32-bit integer can hold. Any system still storing time in a 32-bit field cannot represent it, and instead of a date in 2038 it produces a date in 1901. The tool flags anything approaching that limit, which is worth knowing before a column of future expiry dates goes into a legacy table.
A negative timestamp gets flagged too. Dates before 1970 are valid Unix time and are rejected outright by some languages and database drivers, which is a common surprise when importing historical records.
🟢 Using The Meeting Planner
Set the instant on the Convert tab, then open World Clock and add the zones you care about. The grid shows one full day across every zone at once.
- 🔵 Green means that hour falls inside working hours on a weekday in that zone.
- 🟠 Amber marks the hour either side, which is usually workable if someone is willing.
- 🟣 A dark cell means every zone in your list is inside working hours at the same moment – that is your meeting slot.
The DST badge next to each zone matters more than it looks. Daylight saving shifts a zone by an hour twice a year, and the shift dates differ between countries. A slot that works in June may not work in November, and the badge tells you which state you are currently looking at.
🟡 Two Jobs Worth Knowing
Making sense of a log file
Copy the timestamp column out of the log, paste it into the Batch tab, choose your output format and press Convert All. Detection handles the seconds-or-milliseconds question automatically. Download the CSV and paste the readable column beside the original.
Working out when something actually expires
Paste the expiry timestamp, read the relative line – it says something like in 4 months – and check the 2038 warning has not fired. Then use the Date Calculator to work out the renewal date thirty days before it.
🔴 Common Mistakes and Real Limits
- 🔵 Confusing seconds with milliseconds. A ten-digit number is seconds; thirteen digits is milliseconds. Feed milliseconds into a seconds field and you land somewhere around the year 57000.
- 🟠 Assuming an offset is a time zone.
+05:30is an offset at one moment.Asia/Colombois a zone with a full history of rule changes. Storing the offset alone loses the information needed for future dates. - 🟣 Excel serial numbers are days, not seconds. They also count from 1899, and the spreadsheet’s own leap-year quirk is built into the number. Never treat one as an epoch value.
- 🔵 Business days here exclude weekends only. Public holidays differ by country and are not applied, so treat the count as a starting figure rather than a payroll answer.
- 🟠 Leap seconds are not counted. Unix time deliberately ignores them, so a duration across a leap second is off by a second. That matches every standard system and is almost never a problem outside scientific work.
- 🟣 Some local times do not exist. On the morning clocks jump forward, an hour is skipped entirely. The Date Calculator tab tells you when the time you entered is one of those, instead of quietly moving it.
Frequently Asked Questions
Is my data sent anywhere?
No. Every calculation uses the date engine already in your browser. No library is downloaded and nothing you paste leaves your device.
How do I tell seconds from milliseconds?
Count the digits. Ten digits is seconds and thirteen is milliseconds for any date near today. The Paste box works this out for you automatically.
What is the 2038 warning about?
A signed 32-bit integer runs out on 19 January 2038. Systems still using one cannot store a later time and wrap around to 1901 instead, so future dates are flagged before you save them.
Why is an Excel serial number so small?
Because it counts days rather than seconds, starting from 1899. A date in 2026 is roughly forty-six thousand days later, which is why the number looks nothing like an epoch value.
Can I convert a whole column at once?
Yes. Paste one timestamp per line into the Batch tab, pick an output format, and download the result as a CSV with the original and converted values side by side.
Does the meeting planner handle daylight saving?
Yes. Each zone shows whether daylight saving is active on the selected date, and the grid uses the real offset for that date rather than a fixed one.
Are public holidays counted in business days?
No. Only Saturday and Sunday are excluded, because holidays vary by country and region. Treat the figure as a starting point rather than a final answer.
What happens with a date before 1970?
It converts normally and produces a negative timestamp, which is valid Unix time. A warning appears because some languages and database drivers refuse negative values.
Can I schedule a recurring job here?
No, this page converts single instants. Recurring schedules are cron expressions, which the Cron Studio Pro builds, explains in plain English and previews.
