UNIX TimestampConverter
Convert between Unix epoch timestamps and human-readable dates instantly. Support for seconds, milliseconds, and local timezones.
What Is a UNIX Timestamp?
A UNIX timestamp is a numeric representation of time. It counts the exact number of seconds that have elapsed since the Unix Epoch (January 1, 1970, at 00:00:00 UTC). This integer-based approach makes it incredibly efficient for computers to process, store, and compare dates. Conversion is necessary because while computers love integers, humans need readable dates. For a deep dive into the history, read our Unix Timestamp Guide.
How To Use the Converter
Using our Unix Timestamp Converter is designed to be completely frictionless. Follow these step-by-step instructions:
- To convert Epoch to Date: Paste your integer into the "Timestamp" input field. The tool will automatically detect if it is in seconds or milliseconds and immediately display the corresponding local time and UTC time.
- To convert Date to Epoch: Switch to the "Date to UNIX" tab. Use the date picker to select a local calendar date and time. The tool will generate the precise 10-digit (seconds) and 13-digit (milliseconds) Unix timestamps.
- Copy and Paste: Click the copy icon next to any output to instantly copy the exact string to your clipboard for use in your codebase.
Unix Timestamp Examples
Here are 10 notable examples of Unix timestamps throughout history. Notice how dates prior to 1970 use negative integers.
| Event / Date | Unix Timestamp (Sec) | UTC Date |
|---|---|---|
| Moon Landing | -14159040 | July 20, 1969 20:17:40 |
| Unix Epoch | 0 | January 1, 1970 00:00:00 |
| 1 Million Seconds | 1000000 | January 12, 1970 13:46:40 |
| 100 Million Seconds | 100000000 | March 3, 1973 09:46:40 |
| Y2K Bug | 946684800 | January 1, 2000 00:00:00 |
| 1 Billion Seconds | 1000000000 | September 9, 2001 01:46:40 |
| Bitcoin Genesis Block | 1231006505 | January 3, 2009 18:15:05 |
| Discord App Launch | 1431561600 | May 14, 2015 00:00:00 |
| Y2K38 Problem | 2147483647 | January 19, 2038 03:14:07 |
| 2 Billion Seconds | 2000000000 | May 18, 2033 03:33:20 |
Common Use Cases
Unix timestamps are the backbone of modern web architecture. Here are the primary use cases:
- APIs: JSON payloads often transmit dates as integers to save bandwidth and prevent parsing errors. Converting these integers to verify correctness is a daily developer task.
- Databases: Storing dates as
BIGINTallows for blazing-fast sorting and indexing compared to string-based datetime columns. - Logging: High-performance server logs append a Unix timestamp to every event to ensure events are strictly ordered.
- Analytics and Event Tracking: Tracking pixels and analytics scripts use precise millisecond timestamps to calculate user session durations.
- Discord Bots: Using our Discord Timestamp Generator, bots dynamically localize time for users globally.
Timestamp Formats (Seconds vs Milliseconds vs UTC)
Understanding the format of your integer is crucial.
- Seconds (10-digits): The standard format used by Unix systems, Python, PHP, and most backend servers. Example:
1697297400. - Milliseconds (13-digits): The standard format used by JavaScript and Java, offering higher precision. Example:
1697297400000. - UTC: Remember, the integer itself is always in UTC (Coordinated Universal Time). Timezones are only relevant when rendering the integer as a human-readable string. Explore our World Timezones map for more.
UTC Conversion Examples
Because Unix time is implicitly based on UTC, converting an integer to UTC is straightforward. Let's explore some common UTC conversions:
0converts exactly to Jan 1, 1970 00:00:00 UTC.1704067200converts to Jan 1, 2024 00:00:00 UTC.2147483647(The Y2K38 limit) converts to Jan 19, 2038 03:14:07 UTC.
For complete understanding of how this differs from local time, read our UTC vs GMT Comparison.
UTC Offset Examples
Localizing a Unix timestamp involves applying a UTC offset. Our converter does this automatically, but here is what the math looks like behind the scenes (for more details, see our UTC Offset Guide):
- UTC-5 (EST): To find local time from Unix
1700000000, you format the UTC date and subtract 5 hours. - UTC+1 (CET): You add 1 hour to the UTC representation.
- UTC+5:30 (IST): You add 5 hours and 30 minutes to the UTC time. Explore all regions on our World Timezones map.
GMT Conversion Examples
Since GMT shares the same time as UTC, converting a Unix timestamp to GMT yields the identical clock time. For example, the timestamp 1600000000 is exactly Sept 13, 2020 12:26:40 GMT. Learn more about the history of this time zone in our GMT Complete Guide.
API Integration Examples
When dealing with APIs (like Stripe, Discord, or Twitter), you will often receive integer timestamps. Always assume these are UTC-based integers.
- Stripe API: Uses 10-digit seconds timestamps for
createdproperties. - Discord API: Also uses seconds, but Discord users often use special syntax to render timestamps. Refer to our Discord Timestamp Guide for community formatting.
Developer Code Examples
Here is how to safely convert Unix timestamps to readable UTC strings in popular languages:
const date = new Date(timestamp * 1000);
console.log(date.toUTCString());
timestamp = 1700000000
print(datetime.datetime.fromtimestamp(timestamp, tz=datetime.timezone.utc))
Common Errors to Avoid
- Wrong Unit (Sec vs Ms): Feeding a 13-digit millisecond timestamp into a function expecting a 10-digit second timestamp will output a date in the year 50,000+. Always verify your unit.
- Wrong Timezone Adjustments: Developers often mistakenly add or subtract hours directly to the Unix integer. Never modify the base integer for timezone corrections; handle timezone offsets during string formatting via libraries like
date-fnsormoment.js. - ISO 8601 Confusion: If an API expects an ISO 8601 string and you pass an integer, the request will fail. Ensure strict typing.
Frequently Asked Questions
What is a UNIX timestamp?
A UNIX timestamp is a system for tracking time as a running total of seconds. The count starts at the Unix Epoch, which is January 1st, 1970 at 00:00:00 UTC.
What is epoch time?
Epoch time refers to the starting point of the UNIX timestamp system, specifically January 1, 1970 UTC. Time is measured as the number of seconds or milliseconds elapsed since this epoch.
How do I convert a UNIX timestamp to a readable date?
You can convert a UNIX timestamp to a readable date by entering the timestamp into our UNIX Timestamp Converter tool. It automatically translates the seconds or milliseconds into a human-readable date and time.
How do I convert a date to UNIX timestamp?
Select your desired date and time in the 'Date to UNIX' tab of our converter. The tool will calculate and provide the corresponding UNIX timestamp in both seconds and milliseconds.
Why does UNIX time start in 1970?
UNIX time starts in 1970 because early UNIX engineers needed a uniform date to serve as a reference point (an epoch) for system clocks, and January 1, 1970 was chosen as a convenient, arbitrary start date.
What is the difference between seconds and milliseconds timestamps?
A standard UNIX timestamp is a 10-digit number representing seconds. A 13-digit timestamp represents milliseconds, offering higher precision. JavaScript typically uses milliseconds, while backend systems often use seconds.
Are UNIX timestamps always UTC?
Yes, a UNIX timestamp is inherently independent of timezones and is based on Coordinated Universal Time (UTC). It represents the exact same moment in time globally, regardless of local timezones.
How accurate are UNIX timestamps?
UNIX timestamps are extremely accurate for measuring elapsed time and ordering events. Depending on the system, they can track time down to milliseconds, microseconds, or even nanoseconds.
Why do developers use UNIX timestamps?
Developers use UNIX timestamps because they are simple integers, avoiding complexities like timezones, daylight saving time, and formatting differences across databases, APIs, and operating systems.
What happens during the Year 2038 problem?
The Year 2038 problem occurs because a 32-bit integer cannot store a UNIX timestamp beyond January 19, 2038. Systems must upgrade to 64-bit integers to accurately represent dates past this point.
How do I get the current Unix timestamp in Python?
You can use the 'time' module: int(time.time()) will return the current Unix timestamp in seconds.
How do I get the current Unix timestamp in JavaScript?
You can use Math.floor(Date.now() / 1000) to get the standard 10-digit Unix timestamp in seconds.
How do I use Unix timestamps in Discord?
Discord uses a special markdown format <t:UNIX_TIMESTAMP:FORMAT> to display localized time. Check out our Discord Timestamp Guide for more details.
Is POSIX time the same as Unix time?
Yes, POSIX time is the formal name for Unix time, defined by the IEEE standards for operating systems.
Can a Unix timestamp be negative?
Yes, a negative Unix timestamp represents a date prior to the Unix Epoch (January 1, 1970). For example, -86400 is December 31, 1969.
Do Unix timestamps account for leap seconds?
No, Unix time formally ignores leap seconds. Every day is treated as exactly 86,400 seconds.
How do databases store Unix timestamps?
Most databases store them as BIGINT (64-bit integer) to avoid the Y2K38 overflow problem and ensure efficient indexing.
Can I convert ISO 8601 strings to Unix time?
Yes, our converter automatically parses ISO 8601 strings and outputs the precise Unix epoch integer.
Why is my timestamp showing the year 50,000?
This happens when you accidentally pass a 13-digit millisecond timestamp to a function that expects a 10-digit second timestamp.
What is the maximum Unix timestamp for a 64-bit integer?
A 64-bit integer can hold a timestamp that equates to a date roughly 292 billion years in the future, safely resolving the Y2K38 problem.
Explore Related Resources
Continue learning with our comprehensive time guides. Read our Unix Timestamp Guide for an in-depth technical dive. Check out the Discord Timestamp Guide to learn how to dynamically localize times for gaming communities using our Discord Timestamp Generator. Ensure strict string validation with our ISO 8601 Converter and compare global offsets via our World Timezones portal.