Current Unix Timestamp
1 Timestamp → Date
2 Date → Timestamp
3 Batch Converter
Enter one timestamp per line (auto-detects seconds vs milliseconds)
4 Countdown Timer
Unix Timestamp Converter
What is a Unix Timestamp?
A Unix timestamp (also known as Unix time, POSIX time, or Unix epoch time) is a system for representing a point in time as the number of seconds that have elapsed since the Unix Epoch — January 1, 1970, at 00:00:00 UTC. This simple numeric representation is the foundation of timekeeping in virtually all modern computer systems, programming languages, databases, and APIs.
Unix timestamps are widely used because they are timezone-independent, easy to store as a single integer, and simple to compare and compute with. When you see a timestamp like 1700000000, it represents a specific moment in time that is the same regardless of where in the world you are. This makes timestamps ideal for logging events, scheduling tasks, and exchanging time data between distributed systems.
This converter supports both second-precision timestamps (typically 10 digits) and millisecond-precision timestamps (13 digits), which are commonly used in JavaScript and many modern APIs. The tool auto-detects the unit and provides conversions in multiple human-readable formats including ISO 8601, UTC, and your local timezone.
Common Timestamps Reference
| Timestamp | Date (UTC) | Description |
|---|---|---|
| 0 | 1970-01-01 00:00:00 | Unix Epoch (the beginning of time) |
| 86400 | 1970-01-02 00:00:00 | Exactly one day after epoch |
| 1000000000 | 2001-09-09 01:46:40 | One billion seconds milestone |
| 1234567890 | 2009-02-13 23:31:30 | Culturally notable timestamp |
| 1609459200 | 2021-01-01 00:00:00 | Start of year 2021 |
| 1700000000 | 2023-11-14 22:13:20 | Recent round number milestone |
| 2147483647 | 2038-01-19 03:14:07 | Max 32-bit signed int (Y2038 problem) |
How Timestamps Work
The Unix timestamp counts the number of seconds since the epoch date. Positive values represent dates after January 1, 1970, while negative values represent dates before it. For example, a timestamp of 86400 equals exactly one day (60 seconds × 60 minutes × 24 hours = 86,400 seconds) after the epoch, which is January 2, 1970, 00:00:00 UTC.
In JavaScript, the Date.now() method returns the current time in milliseconds since the epoch. The expression Math.floor(Date.now() / 1000) gives you the standard seconds-based Unix timestamp. Many backend systems and APIs (such as PostgreSQL, MySQL, Redis, and most REST APIs) use second-precision timestamps, while JavaScript and Java typically use millisecond precision.
The Y2038 problem is a potential issue for systems using 32-bit signed integers to store Unix timestamps. The maximum value for a signed 32-bit integer is 2,147,483,647, which corresponds to January 19, 2038, at 03:14:07 UTC. After this moment, such systems may overflow. Modern 64-bit systems can represent timestamps far into the future, effectively solving this issue for all practical purposes.
Frequently Asked Questions
What is the difference between seconds and milliseconds timestamps?
A seconds-based Unix timestamp is a 10-digit number representing seconds since the epoch (e.g., 1700000000). A milliseconds-based timestamp is a 13-digit number representing milliseconds since the epoch (e.g., 1700000000000). JavaScript's Date.now() returns milliseconds, while most server-side systems and databases use seconds. This tool auto-detects which format you are using based on the number of digits.
Why do my local results differ from UTC?
Unix timestamps are always in UTC (Coordinated Universal Time). When displaying "Local Time," the converter adjusts the timestamp to your device's timezone setting. If you are in UTC+8 (e.g., China Standard Time), the local time will be 8 hours ahead of UTC. The timezone selector above lets you view the time in any timezone regardless of your device settings.
Can I convert negative timestamps?
Yes. Negative Unix timestamps represent dates before the Unix Epoch (January 1, 1970). For example, -86400 represents December 31, 1969, at 00:00:00 UTC. This is useful for historical date calculations. Simply enter a negative number in the timestamp input field.
What is ISO 8601 format?
ISO 8601 is an international standard for representing dates and times. The format is YYYY-MM-DDTHH:mm:ss.sssZ, where "T" separates the date from the time, and "Z" indicates UTC timezone. For example, 2023-11-14T22:13:20.000Z. This format is widely used in APIs, JSON data, and international communications because it is unambiguous and lexicographically sortable.