Current Unix time

seconds —

milliseconds —

Timezone

Unit

Unix Timestamp → Date

Local date & time

—

UTC / ISO 8601

—

Selected timezone

—

Relative time

—

Day of week

—

Week of year

—

Date & Time → Unix Timestamp

Date

Time

Unix (seconds)

—

Unix (milliseconds)

—

ISO 8601

—

What is a Unix timestamp?

Seconds elapsed since 1 Jan 1970 00:00:00 UTC
Also called Unix time, POSIX time, or Epoch time
Timezone-independent — always relative to UTC
Universally used in databases, APIs, and log files

Seconds vs. milliseconds

10 digits = seconds (Unix/POSIX standard)
13 digits = milliseconds (used by JavaScript)
19 digits = nanoseconds (Go, Rust, Linux syscalls)
Select the right unit above to avoid off-by-1000x errors

How to use this tool

Enter a Unix timestamp or click Use now
Select the unit (s / ms / ns) for correct interpretation
Or pick a date & time to get its Unix equivalent
Switch timezone to see any date in a different locale

100% private & client-side

All calculations done with native browser Date API
Zero data transmitted to any server
Works offline after initial page load
Timezone formatting via Intl.DateTimeFormat

The Year 2038 problem — what every developer should know

Traditional 32-bit Unix timestamps can only represent dates up to 19 January 2038, 03:14:07 UTC. After that, the counter overflows back to a negative value, causing the dreaded "Year 2038 problem" (analogous to Y2K). Systems that store timestamps as 32-bit signed integers — many embedded devices, older databases, and legacy POSIX APIs — are vulnerable. Modern systems and languages use 64-bit timestamps, which can represent dates billions of years into the future. Always prefer 64-bit storage for any new code you write, and be aware when interfacing with older systems or binary protocols that assume 32-bit epoch values.