Unix Timestamp Converter - Free Epoch to Date

This Unix timestamp converter turns epoch numbers into readable dates and turns dates back into timestamps. Paste a number in seconds or milliseconds to see UTC, local time, ISO 8601 and a relative description, or pick a date and time to get the matching timestamp. It is free and needs no sign-in.

What Is a Unix Timestamp?

A Unix timestamp is the number of seconds that have passed since 00:00:00 UTC on January 1, 1970, a moment known as the Unix epoch. Because it is one number with no time zone attached, it gives systems a compact, unambiguous way to store and compare moments in time.

The value 0 is the epoch itself, 86400 is exactly one day later (24 × 60 × 60 seconds), and negative numbers point to moments before 1970. Many systems also store the same moment in milliseconds, which is the seconds value multiplied by 1,000. JavaScript dates, many web APIs and some log formats work this way.

Seconds or milliseconds: how can you tell?

The fastest check is to count digits. Timestamps for present-day dates have 10 digits in seconds and 13 digits in milliseconds.

The Auto option follows the same idea. When the absolute value of your number is above 9999999999, it is read as milliseconds. Anything at or below that is read as seconds.

How to Use the Unix Timestamp Converter

You can convert in both directions on one page, and each direction has its own button. Follow these steps.

1. Look at the Current Unix Timestamp panel at the top. It ticks every second and shows the matching UTC date. Use the copy icon beside it to copy the number.
2. To decode a timestamp, type or paste it into the field under Timestamp → Date. The hint shows the format, for example 1700000000.
3. Open Timestamp unit and choose Seconds, Milliseconds or Auto. Auto is a safe default when you are not sure which unit you have.
4. Click Convert to Date. Four lines appear: UTC, Local, ISO 8601 and Relative.
5. To go the other way, pick a date and time in the field under Date → Timestamp. It starts at your current local time and accepts seconds.
6. Click Convert to Timestamp to get the value in Seconds and in Milliseconds.

Changing the input or the unit clears the previous result, so you never read a stale answer.

Worked Example: Converting 1700000000

Entering 1700000000 with the unit set to Seconds (or Auto) shows a UTC time of Tue, 14 Nov 2023 22:13:20 GMT and an ISO 8601 value of 2023-11-14T22:13:20.000Z. The Local line depends on your device. A computer set to US Central time shows 4:13:20 PM on the same day, and one set to US Eastern shows 5:13:20 PM.

The Relative line tells you how far that moment is from now, so for a date in 2023 it reads as a past event. If you type 1700000000000 instead, Auto sees a 13-digit number, treats it as milliseconds and returns the exact same date.

Now try the reverse. Say you want the timestamp for midnight on January 1, 2024. On a device set to UTC, entering 2024-01-01 00:00:00 returns 1704067200 seconds. On a device set to US Central (UTC-6), the same entry returns 1704088800, because midnight in Chicago happens six hours after midnight in UTC (1704067200 + 21,600). Both answers are correct. They describe different moments.

How Do You Read and Act on the Results?

Each result line answers a different question, so use the one that matches your task.

UTC

UTC is the neutral reference time. Use it when you compare values from servers, logs or teammates in different regions, because it does not shift with daylight saving time.

Local

Local shows the same moment in your device's time zone and date format. Use it to answer "when did this happen for me?" Do not paste it into code or a spreadsheet shared with others, since it changes with each viewer's settings.

ISO 8601

ISO 8601 is the standard text format, such as 2023-11-14T22:13:20.000Z. The trailing Z means UTC. It is the safest choice for APIs, databases, and fields such as the lastmod date in an XML sitemap.

Relative

Relative gives a quick sanity check. If a "created" timestamp should be from last week but the result says several decades ago, you are probably reading the wrong unit.

Quick sanity checks

• A result in January 1970 means a milliseconds value was read as seconds, or the value is tiny by design.
• A result thousands of years in the future means a milliseconds value was read as seconds. Switch the unit to Milliseconds or Auto.
• A result off by a whole number of hours usually means you compared Local with UTC.

How Do You Convert a Unix Timestamp in Excel, Google Sheets, SQL or Python?

Each platform has a short pattern, and you can confirm your result against this page. Use these as starting points.

• Excel and Google Sheets: with a seconds value in A2, enter =A2/86400+DATE(1970,1,1) and format the cell as date and time. For milliseconds, divide by 86400000 instead.
• SQL (MySQL): FROM_UNIXTIME(1700000000) returns a date and time in the database session's time zone.
• Python: datetime.fromtimestamp(1700000000, tz=timezone.utc) returns an aware UTC datetime.
• JavaScript: new Date(1700000000 * 1000), because the constructor expects milliseconds.
• Discord: a timestamp tag uses seconds, written as <t:1700000000:F>. Convert your target date here, copy the Seconds value and put it in the tag.

If your spreadsheet answer differs from this page by several hours, the difference is almost always the time zone setting, not the formula.

Who Needs a Timestamp Converter?

Anyone who meets raw epoch numbers benefits from a quick decoder. These are the common situations.

• Developers check API responses, token expiry values and database rows without writing throwaway code.
• Site owners and SEOs read server logs and analytics exports to see exactly when a crawler visit or an error occurred.
• Database and data analysts clean exports where dates arrive as 10 or 13 digit numbers.
• Community managers create Discord timestamps that display correctly in every member's time zone.
• Support teams turn a customer's "it failed at 1700000000" into a date they can search for.

If you work with dates in other ways, the age calculator measures the elapsed time between a birth date and today, and the online calculators and utilities hub lists related helpers.

Best Practices, Common Mistakes and Troubleshooting

Store and exchange UTC

Keep timestamps and ISO 8601 values in UTC in your systems. Convert to local time only when you display a date to a person.

Use whole numbers only

The timestamp field accepts digits with an optional plus or minus sign. A value such as 1700000000.5, a number with commas, or text with spaces inside shows the message "Enter a whole timestamp within the safe integer range." Remove the decimal part or separators and try again.

Fix "outside the supported date range"

This message appears when the number is too large to be a real date. It usually means a very long value, such as a microsecond or nanosecond timestamp (16 or 19 digits). Divide it by 1,000 for each step down: microseconds to milliseconds, then pick Milliseconds.

Fix "Enter a valid date and time"

This appears when the date field is incomplete or invalid. Fill in the full date and time, including the time portion, and click Convert to Timestamp again.

Do not force the wrong unit

Choosing Seconds for a 13-digit number gives a date tens of thousands of years away. Choosing Milliseconds for a 10-digit number gives a date in January 1970. When the result looks absurd, switch the unit first.

Know the 2038 limit

Systems that store seconds in a signed 32-bit integer overflow after 2147483647, which is January 19, 2038, 03:14:07 UTC. You can paste that number here to see it. To explore why that limit exists, the binary calculator shows how 31 bits of ones add up to that value.

Limitations and Accuracy Notes

The converter works with whole numbers, so fractional seconds in the timestamp field are not accepted. When you convert a date to a timestamp, the seconds value is rounded down to the whole second, while the milliseconds value keeps the exact figure.

The date picker reads the date and time you choose as your device's local time. There is no separate time zone selector. To get a timestamp for a specific zone, work out the offset or set your device to that zone. Leap seconds are not counted in Unix time, which is why every day is exactly 86,400 seconds long.

Use the converter above to decode a number from a log, check an API value or build a timestamp for your next project. Paste the number or choose a date, click the convert button, and copy the result you need.