Unix Timestamp Converter: a practical guide
Convert Unix seconds or milliseconds into UTC dates and back.
Open Unix Timestamp ConverterWhen this is useful
Unix timestamps count time since the UTC epoch at the start of 1970. API payloads commonly use seconds, while JavaScript dates use milliseconds. A value interpreted with the wrong unit can point decades away from the date you intended.
A reliable workflow
Choose the unit explicitly, paste an integer timestamp, and convert it to an ISO UTC date. For the reverse direction, the date-time field is explicitly interpreted as UTC. It does not infer the time zone of an office or a city from your browser.
Example input: 1704067200
What to check before you finish
Use zero as a test: it corresponds to 1970-01-01T00:00:00.000Z. Negative timestamps refer to dates before the epoch. Check the API’s documented precision and avoid treating Unix time as a model for every leap-second or civil-time calculation.
Keep the next step simple
Open the Unix Timestamp Converter above to try the workflow. Your input is processed in your browser, without an account or file uploads. The related tools below can help with the next step; check the output before publishing it or adding it to a production system.