I use D-MMM-YYYY format for dates, with the English (US) locale. Excel supports entering dates in the forms: DMMM, DMMMYY, DMMMYYYY : E.g. 5jun, 14May02, 7jul2023 D-MMM, D-MMM-YY, D-MMM-YYYY : E.g. 5-Jun, 14-May-02, 7-Jul-2023 where the '-' delimiter is optional, the month is case-invariant, and the year defaults to current. But libreoffice Calc does not. These forms are unambiguous, but tools->options->Languages->Formats->Date Acceptance patterns does not accept them. This is consistent with the Help. I'd like the date acceptance patterns to work without delimiters when not ambiguous and to accept alphabetic month names. This would allow input and output to be in the same format. And compatible with Office muscle memory... Ideally, date acceptance patterns would accept all the date format codes used for display, providing that the string is unambiguous. Adjacent numeric fields are ambiguous - e.g. 219, but (as currently), with a delimiter can be resolved based on the format codes. Note that Excel also supports D/M, D/M/YY, D/M/YYYY, which LibreOffice does handle.
Confirmed Version: 25.8.3.2 (X86_64) Build ID: 8ca8d55c161d602844f5428fa4b58097424e324e CPU threads: 16; OS: Linux 6.17; UI render: default; VCL: kf5 (cairo+wayland) Locale: en-US (pt_BR.UTF-8); UI: en-US Calc: threaded