Seconds since 1970, translated
Convert Unix timestamps to readable UTC dates or turn a date into epoch seconds. Detects automatically whether you pasted seconds or milliseconds.
Logs, APIs and databases store time as a single number: seconds elapsed since 1 January 1970 UTC. It is compact and timezone-free, and completely unreadable at a glance.
The persistent trap is seconds versus milliseconds. JavaScript works in milliseconds while most backends use seconds, so a value can land you in 1970 or in the year 56000. This tool detects which one you pasted.
The ISO 8601 UTC timestamp and a human-readable date Automatic detection of seconds versus milliseconds How many days the timestamp sits from today All output is UTC, deliberately — epoch time carries no timezone. Values above roughly 10¹² are treated as milliseconds. How do I tell seconds from milliseconds? By length. Current timestamps in seconds have 10 digits; in milliseconds they have 13. This tool decides for you and tells you which it assumed.
Why 1970? Unix engineers needed an arbitrary origin and picked the start of the decade they were working in. It stuck, and now most of computing counts from it.
What is the year 2038 problem? A signed 32-bit integer overflows on 19 January 2038, wrapping to 1901. Modern systems use 64-bit time, which lasts longer than the sun will.
Does epoch time include leap seconds? No, and that is intentional. Unix time pretends every day has exactly 86,400 seconds, which keeps arithmetic simple at the cost of being fractionally out of step with astronomical time.
Worked example The start of epoch time
Input: 0
Output: 1970-01-01T00:00:00.000Z
Note: A timestamp of 0 usually means a field was never set. Seeing 1970 in a log is a null in disguise.
