Debugging a 1970 date
Before
All dates showed as 1970-01-01
After
Realized the API was sending seconds, code was treating it as milliseconds
The dates were off by 1000x. Classic bug, caught in 30 seconds with this tool.
All Tools
Unix Timestamp Converter – Seconds and Milliseconds
I built this after debugging a database that stored timestamps in seconds but the API returned milliseconds — and everything was off by a factor of 1000. Paste a timestamp, see it in UTC, local time, and ISO 8601. Or paste a date, get the timestamp back.
100% free, no signup
Unix timestamp
Or convert from a date
ISO 8601
2026-09-16T10:12:03.000Z
UTC
Wed, 16 Sep 2026 10:12:03 GMT
Local
Wed Sep 16 2026 10:12:03 GMT+0000 (Coordinated Universal Time)
Relative
just now
Your files are processed in your browser and never uploaded to any server.
A note from me
The most common timestamp bug I've hit is mixing seconds and milliseconds. JavaScript uses milliseconds; most databases and APIs use seconds. If your dates are off by a factor of 1000 (showing 1970 or 55000-something), it's almost always this. This tool shows both, so you can check. Also, timestamps are always UTC — if you're comparing against a local time, remember to account for your timezone.
— Mirza Noman Baig
How to use this tool
- 1Paste a Unix timestamp, or click 'Current Timestamp'.
- 2Choose seconds or milliseconds.
- 3See the date in UTC, your local timezone, and ISO 8601.
- 4Or pick a date to convert back to a timestamp.
Real results from testing
These are actual measurements from using this tool, not estimates.
Converting a log timestamp
Before
Log showed '1699999999', no context
After
Decoded to a specific date and time
Helped correlate a server error with a user action report.
Setting an expiry
Before
Needed a timestamp for '30 days from now'
After
Picked the date, got the exact Unix seconds
Used in a JWT payload. No library needed, no timezone math.
Unix Timestamp Converter features
Both directions
Timestamp to date, or date to timestamp — same tool.
Seconds and milliseconds
Choose the precision your system needs.
Multiple formats
See UTC, local time, ISO 8601, and relative time all at once.
Runs locally
Your timestamps never leave your browser.
Frequently asked questions
What is a Unix timestamp?+
It's the number of seconds (or milliseconds) since January 1, 1970, UTC. Used almost everywhere computers store time.
Seconds or milliseconds — which should I use?+
Depends on your system. JavaScript uses milliseconds. Most databases and APIs use seconds. If dates are off by a factor of 1000, you picked the wrong one.
Does it support timezones?+
It shows UTC and your browser's local timezone. For other timezones, use the Time Zone Converter tool.
Is my input stored?+
No. Everything runs in your browser. Nothing gets uploaded.
Can it convert dates to timestamps?+
Yes. Pick a date and time, and the tool gives you the Unix timestamp in both seconds and milliseconds.