What this tool is good for
This timestamp converter can switch between Unix timestamps in seconds, timestamps in milliseconds, ISO 8601, ISO 9075, local date strings, and UTC output. It is useful for API debugging, log analysis, database checks, and cross-language development.
The string format labels on this page follow common ISO 8601 and ISO 9075 naming, while the rendered local-time output still depends on the viewer's runtime timezone.
Typical use cases
- Verify whether a backend returns seconds or milliseconds.
- Turn a timestamp from logs into a readable date and time.
- Check for timezone offsets between backend and frontend systems.
- Copy ISO 8601, UTC, or local time strings into test scripts and database statements.
How to use it
- Enter a timestamp or a date string and the tool detects the format automatically.
- Review the results in seconds, milliseconds, ISO, UTC, and local formats.
- Copy the exact output required by the next system.
Example
Input: 2024-01-01T00:00:00Z
Timestamp (seconds): 1704067200
Timestamp (milliseconds): 1704067200000
This kind of side-by-side comparison is especially useful when debugging APIs that accidentally mix seconds and milliseconds.
Code examples
These examples use explicit UTC input so the numeric results stay stable across timezones:
// JavaScript
Math.floor(Date.parse("2024-01-01T00:00:00Z") / 1000); // 1704067200
new Date(1704067200 * 1000).toISOString(); // 2024-01-01T00:00:00.000Z
# Python
from datetime import datetime, timezone
datetime.fromisoformat("2024-01-01T00:00:00+00:00").timestamp() # 1704067200.0
datetime.fromtimestamp(1704067200, tz=timezone.utc).isoformat() # 2024-01-01T00:00:00+00:00
<?php
strtotime("2024-01-01T00:00:00Z"); // 1704067200
gmdate("c", 1704067200); // 2024-01-01T00:00:00+00:00
FAQ
What is the difference between 10-digit and 13-digit timestamps?
A 10-digit value usually means a Unix timestamp in seconds, while a 13-digit value usually means milliseconds. Many integration bugs come from interpreting milliseconds as seconds or the other way around.
Why does the same time look different in different systems?
Timezone differences are the most common reason. A UTC time can appear differently in a local environment, so verify whether both systems are using UTC or local time before troubleshooting further.
Why can a normal date string become invalid?
Ambiguous date formats, typos, or missing separators often cause parsing failures. Standard formats such as ISO 8601 are usually the most reliable choice.
Why does an empty input show the current time immediately?
That default makes it faster to inspect the current moment across multiple output formats when you just need a quick timestamp or standard time string.
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