Timestamp Converter
Paste an epoch timestamp or a date and get it in the zone you care about. The unit is detected from the magnitude, and any local time that falls in a daylight-saving gap or repeat is called out rather than silently resolved.
Output appears here as you type.
Runs entirely in your browser. Nothing you paste here is uploaded or stored.
Questions
Does anything get sent anywhere?
No. Both tools are pure functions in your tab, using the time zone database your browser already ships. The page cannot open a network connection — its Content-Security-Policy sets connect-src to ‘none’.
Why does it matter whether a local time is ambiguous?
Because twice a year a wall-clock reading is either missing or doubled. When clocks go forward, 02:30 simply does not occur — a job scheduled then may not run at all. When they go back, 01:30 occurs twice, and a job scheduled then may run twice. Both are real outages that get diagnosed as flaky infrastructure, and neither is visible in a converter that quietly picks one instant.
How does it know whether my number is seconds or milliseconds?
From its magnitude. Ten digits is seconds, thirteen is milliseconds, sixteen microseconds, nineteen nanoseconds — the ranges do not overlap for any date in the modern era. You can override it if your value is genuinely outside that.
The date is a day out from what I expected.
Almost always a zone difference rather than a wrong timestamp. An instant near midnight falls on different calendar days depending on where you read the clock, which is why every line here carries its offset rather than an abbreviation alone.