Choose the format before converting
- Select the input format used by your date text and the desired output format.
- Enter a real calendar date with the selected separators and digit widths.
- Convert and review the normalized date and weekday before copying or downloading.
Ambiguous dates and examples
29/02/2024 interpreted as DD/MM/YYYY becomes 02/29/2024 in MM/DD/YYYY and 2024-02-29 in YYYY-MM-DD; the weekday is Thursday. 03/04/2024 means April 3 in DD/MM/YYYY but March 4 in MM/DD/YYYY. This tool requires your choice rather than inferring a locale.
Supported input and output formats: YYYY-MM-DD, DD/MM/YYYY, MM/DD/YYYY, DD-MM-YYYY, MM-DD-YYYY, YYYY/MM/DD, DD.MM.YYYY, MM.DD.YYYY and YYYYMMDD. The YYYY-MM-DD full-date ordering is defined in RFC 3339’s date grammar. This converter handles dates alone, not complete timestamp strings.
Limits and privacy
Gregorian dates 0001–9999 with real month lengths and leap-year validation. Input year uses four digits; day and month use two. Surrounding whitespace is trimmed. Two-digit years, month names as input, partial dates, timestamps, spreadsheet serial numbers and automatic format detection are not supported.
Gregorian rules apply even before historical adoption. This changes notation without converting a time zone or changing the calendar date. Weekday is calculated consistently from that date; the English display is not a localization service.
Inputs stay in browser memory without uploads or saved date text. CSV records the trimmed input, input/output format keys, converted/normalized date, weekday and English form. Reset restores the examples and clears results. Undo action restores the original text and both format choices before Today, Example, Reverse or Reset. Editing starts a new state. Copy converted date copies just that date for pasting into another field; the format list also offers individual Copy buttons.
Will it guess whether month or day comes first?
No. Select the actual format. A valid but wrongly selected format can represent a different date, so review the normalized and English outputs.
Will an invalid February 29 roll into March?
No. Invalid dates are rejected rather than normalized into another month.