Description:
Date Format Bug in LibreOffice Calc
Date French settings: That is Day/Month/Year
A input like 11/12/20 give 12 September 2020, but must be 11 December
A input 13/3/21 gives the good date 13 mars 21


Steps to Reproduce:
1.open LibreOffice Calc
2.Select colom A, left mouse: Format Cells
3.Category: Date , Language: French (France) , Format: 31/12/99
4.Go to cell 1A, type 11/12 and press enter
==> 1A turns to 12/11/21 This is not correct, it must be 11/12/21
5.(you are in cell 2A) type 13/2 and enter
==> 2A turns to 13/2/21 This is correct

Actual Results:
1A turns to 12/11/21

Expected Results:
1A must be 11/12/21


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 6.4.7.2
Build ID: 1:6.4.7-0ubuntu0.20.04.1
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3; 
Locale: en-US (en_US.UTF-8); UI-Language: en-US
Calc: threaded