Date formatter
Convert dates between YYYY-MM-DD, YYYY/MM/DD, DD.MM.YYYY, MM/DD/YYYY, RFC 3339, Unix seconds/milliseconds and Excel serial numbers, and render any pattern with YYYY MM DD HH mm ss ddd MMM tokens in English or Chinese.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Result
Everything is computed in UTC: a timestamp is time zone independent, and UTC avoids the repeated or missing hours of daylight saving transitions.
Result
2023-11-14 22:13:20
2023-11-14T22:13:20.000Z2023-11-14T22:13:20+00:002023-11-142023/11/1414.11.202311/14/20231700000000170000000000045244.925926Tuesday2023-W46-2318Available tokens：YYYY four-digit year · YY two-digit year · MMMM full month · MMM short month · MM two-digit month · M month · DD two-digit day · D day · dddd full weekday · ddd short weekday · dd minimal weekday · d ISO weekday number (Mon = 1) · HH 24-hour · hh 12-hour · mm minutes · ss seconds · SSS milliseconds · A AM/PM · Z, ZZ time zone · [text] literal
What this tool does
- Turn the timestamps in logs and API payloads (1700000000, 1700000000000) into readable dates, or the other way round when you need a timestamp for a request.
- Handle Excel or CSV serial numbers: 45292 is simply 2024-01-01, so the five-digit cells exported from a spreadsheet need no manual counting.
- Render your own pattern for docs and copy — YYYY年M月D日, ddd MMM D, YYYY or YYYY-MM-DD HH:mm:ss — with English or Chinese month and weekday names.
- See every common spelling of one instant at once: ISO 8601, RFC 3339, DD.MM.YYYY, MM/DD/YYYY, Unix seconds/milliseconds and the Excel serial number side by side.
Example
Input
1700000000 (input type: detect automatically → Unix seconds)
Output
ISO 8601 (UTC): 2023-11-14T22:13:20.000Z; RFC 3339: 2023-11-14T22:13:20+00:00; YYYY-MM-DD: 2023-11-14; YYYY/MM/DD: 2023/11/14; DD.MM.YYYY: 14.11.2023; MM/DD/YYYY: 11/14/2023; Unix seconds: 1700000000; Unix milliseconds: 1700000000000; Excel serial number: 45244.925926; weekday: Tuesday; ISO week date: 2023-W46-2; day of year: 318
Integers of up to 10 digits are read as Unix seconds and 11–13 digits as milliseconds. Pick the “Excel serial number” type — or type excel:45292 — to have the serial number detected automatically.
Frequently asked questions
Can automatic detection mistake an Excel serial number for a timestamp?
Yes. Plain integers are treated as Unix timestamps: up to 10 digits as seconds and 11–13 digits as milliseconds. A five-digit serial like 45292 would be read as 1970-01-01 12:34:52, so choose “Excel serial number” in the input type — or write excel:45292 — when you mean a spreadsheet serial.
Why is everything displayed in UTC?
A timestamp describes one instant that is independent of where you are, so UTC is the only unambiguous rendering; UTC also has no daylight saving, which would otherwise repeat or skip an hour. Convert the +00:00 offset to your own zone if you need local time.
Why does Excel serial 60 become 1900-02-28?
Excel inherited a bug from Lotus 1-2-3 and treats 1900 as a leap year, so serial 60 stands for the non-existent 1900-02-29. This tool folds 60 onto 1900-02-28 (the same day as 59) and never emits 60 when converting the other way, so a date that does not exist cannot appear.
Can the pattern contain Chinese characters?
Yes — anything that is not a known token is copied through untouched, so YYYY年M月D日 renders 2024年2月29日. To be explicit you can wrap text in square brackets, for example [UTC] YYYY-MM-DD.
How do I tell seconds from milliseconds?
Count the digits: 10 digits (1700000000) are seconds and 13 digits (1700000000000) are milliseconds. You can also force the choice with the “Unix seconds” or “Unix milliseconds” input type; both fields are always shown in the result so you can double-check.
Keywords：date formatdate formatterdate patterntimestamp converterexcel serial numberrfc 3339strftime日期格式化日期格式转换时间戳转换excel 序列号日期模板