Timestamp Converter
Convert between Unix timestamps and human-readable dates. Enter a number for timestamp-to-date or a date string for date-to-timestamp.
Enter a Unix timestamp or a human-readable date to convert between formats.
About Unix Timestamps
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970, at 00:00:00 Coordinated Universal Time (UTC). This reference point is known as the Unix epoch. Because it is a single integer with no embedded time-zone information, it provides an unambiguous way to represent a moment in time across every system, language, and continent.
Seconds vs. Milliseconds
Most Unix-derived systems express timestamps in seconds, producing a 10-digit number for dates in the current era (e.g., 1720000000). JavaScript's Date.now() and Java's System.currentTimeMillis(), however, return milliseconds, yielding a 13-digit number. Confusing the two is one of the most common timestamp bugs — a millisecond value read as seconds places the date tens of thousands of years in the future. This converter supports both formats and lets you toggle between them with a single switch.
Timezone Handling
Unix timestamps are inherently UTC. They do not carry timezone or daylight-saving information. When you convert a timestamp to a human-readable date, the result depends on the viewer's locale. This is why APIs and databases should store and transmit timestamps in UTC (or as raw integers) and only localize them at display time. The ISO 8601 format (2024-01-15T10:30:00Z) is the preferred string representation because it explicitly encodes the timezone offset.
Conversion in Code
Converting timestamps is straightforward in every language. In Python, use datetime.fromtimestamp(ts, tz=timezone.utc). In JavaScript, pass milliseconds to new Date(ts * 1000). In Go, call time.Unix(ts, 0). In each case, remember to handle the seconds-vs-milliseconds distinction and always specify UTC when you need a timezone-independent result.
The Year 2038 Problem
Systems that store Unix timestamps as a 32-bit signed integer will overflow on January 19, 2038, at 03:14:07 UTC. After that moment, the counter wraps to a large negative number, causing dates to jump back to December 1901. Modern operating systems and languages have migrated to 64-bit integers, which push the overflow date billions of years into the future. If you maintain legacy code or embedded systems, auditing timestamp storage width is a critical preventive step. You can use the Cron Parser to schedule recurring checks on time-sensitive infrastructure.
Frequently Asked Questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC — known as the Unix epoch. This single integer representation makes it easy to store, compare, and calculate time differences across systems regardless of timezone or locale settings.
Why do some timestamps have 13 digits?
Thirteen-digit timestamps represent milliseconds since the epoch rather than seconds. JavaScript's Date.now() returns milliseconds, while most Unix command-line tools and languages like Python use 10-digit second-precision timestamps. Divide a 13-digit value by 1000 to convert to seconds.
How do I get the current Unix timestamp?
In JavaScript, use Math.floor(Date.now() / 1000) for seconds. In Python, use int(time.time()). In Bash, run date +%s. Each returns the current second-precision timestamp. You can also use DevDash's Timestamp Converter to instantly see the current time in multiple formats.
What is the Year 2038 problem?
On January 19, 2038, at 03:14:07 UTC, a 32-bit signed integer timestamp overflows. Systems storing time as a 32-bit int will wrap to a negative number, jumping dates back to 1901. Modern systems use 64-bit integers, but legacy code and embedded devices may still be at risk.
What is the difference between Unix timestamp and ISO 8601?
A Unix timestamp is a compact integer (e.g., 1720886400) that's timezone-free and easy to compare. ISO 8601 is a human-readable string format (e.g., 2024-07-13T12:00:00Z) that includes date, time, and timezone. Use timestamps for storage and computation, ISO 8601 for display and APIs.