Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates. Supports both seconds and milliseconds.
Current Unix Timestamp
1/3/2026, 9:30:59 PM
Timestamp to Date
Date to Timestamp
What is a Unix Timestamp?
A Unix timestamp (also called Epoch time, POSIX time, or Unix time) is a way of tracking time as a single number: the count of seconds that have elapsed since January 1, 1970, at 00:00:00 UTC. This moment is called the "Unix Epoch."
For example, the timestamp 1704067200 represents January 1, 2024, at midnight UTC. This simple integer representation makes it incredibly efficient for computers to store, compare, and calculate time differences.
Why Use Unix Timestamps?
- Universal Standard: Unix timestamps work identically across all programming languages, operating systems, and databases.
- Timezone Independent: Timestamps are always UTC, eliminating timezone confusion when storing or transmitting dates.
- Easy Math: Adding 86400 (seconds in a day) gives you tomorrow. Subtracting two timestamps gives duration in seconds.
- Compact Storage: A single 32-bit or 64-bit integer takes less space than date strings.
- Sort-Friendly: Timestamps sort naturally—higher numbers are more recent.
Seconds vs. Milliseconds
Standard Unix timestamps are in seconds (10 digits as of 2001). However, many systems use milliseconds (13 digits) for greater precision:
- Seconds (10 digits):
1704067200- Traditional Unix format, used by most backend systems. - Milliseconds (13 digits):
1704067200000- Used by JavaScript, Java, and many APIs.
This converter automatically detects and handles both formats.
The Year 2038 Problem
On January 19, 2038, at 03:14:07 UTC, 32-bit Unix timestamps will overflow. The maximum value of a signed 32-bit integer (2,147,483,647) will be reached, potentially causing systems to wrap around to negative numbers.
Modern systems use 64-bit timestamps, which won't overflow for another 292 billion years. If you're working with legacy systems, this is something to be aware of for long-term date storage.
Converting Timestamps in Code
Here's how to work with Unix timestamps in popular languages:
// JavaScript
const now = Math.floor(Date.now() / 1000);
# Python
import time; now = int(time.time())
// PHP
$now = time();
// Java
long now = Instant.now().getEpochSecond();
Common Reference Timestamps
| Timestamp | Date (UTC) |
|---|---|
| 0 | January 1, 1970 00:00:00 |
| 1000000000 | September 9, 2001 01:46:40 |
| 1500000000 | July 14, 2017 02:40:00 |
| 2000000000 | May 18, 2033 03:33:20 |
| 2147483647 | January 19, 2038 03:14:07 (32-bit max) |
Timezone Considerations
Unix timestamps are always UTC. When converting to local time, remember to account for timezone offset. This converter shows both UTC and your local time to help avoid confusion.
Common mistake: Treating a timestamp as if it's already in local time. If you're storing user-generated dates, always convert to UTC first, store the timestamp, then convert back to the user's timezone when displaying.
Privacy & Security
This timestamp converter runs entirely in your browser. No data is sent to any server. Your timestamps and dates remain completely private, making this tool safe for working with sensitive scheduling data or debugging production logs.
Frequently Asked Questions
Why does Unix time start on January 1, 1970?
It was a convenient, round date close to when Unix was being developed at Bell Labs. The engineers needed an arbitrary starting point, and this date worked well with their 32-bit systems.
How do I handle negative timestamps?
Negative timestamps represent dates before January 1, 1970. For example, -86400 is December 31, 1969. Not all systems support negative timestamps properly.
What about leap seconds?
Unix time ignores leap seconds. Each day is treated as exactly 86,400 seconds, which can cause minor discrepancies (a few seconds) from astronomical time.
How precise can timestamps be?
Standard Unix timestamps have second precision. For millisecond or microsecond precision, use 13-digit or 16-digit timestamps respectively.