Convert Unix timestamps in seconds or milliseconds to UTC dates, and UTC dates back to timestamps.
● Your files stay yoursChoose the unit explicitly. Seconds allow up to 3 decimal places; milliseconds must be whole numbers.
Use YYYY-MM-DDTHH:mm:ssZ, optionally with .SSS before Z. Z means UTC, not your local time.
Copy becomes available when a result is ready. Editing inputs or options clears the previous result.
Paste a timestamp, select seconds or milliseconds, and choose Convert timestamp. To go the other way, enter a UTC date such as 2024-01-01T00:00:00Z and choose Convert UTC date. The result includes an ISO date and both timestamp units. Use current time fills both inputs from your device clock. For example, 1704067200 seconds and 1704067200000 milliseconds both represent 2024-01-01T00:00:00.000Z.
Unix time counts from 1970-01-01T00:00:00Z: timestamp 0 is that instant, and negative values are earlier. All dates here use UTC, avoiding local daylight-saving ambiguity. Seconds accept up to three decimal places; milliseconds are integers. Dates must include T, seconds, and a final Z; timezone offsets and leap seconds are not accepted. Supported years are 0001–9999 in the Gregorian calendar. Current time depends on your device clock. Inputs never leave your browser.
