It worked in MS Office Excel, but not in LibreOffice Calc.

Hello, people.

Using: Version: 24.8.3.2 (X86_64) / LibreOffice Community
Build ID: 48a6bac9e7e268aeb4c3483fcf825c94556d9f92
CPU threads: 8; OS: Windows 11 X86_64 (10.0 build 26100); UI render: Skia/Vulkan; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: threaded

This calendar was working well in MS Excel 2007,
after some help from a forum because some of
this stuff is above my level of understanding.
I’ve now switched to LibreOffice, and some parts don’t work.
To assist you in debugging, the NOTES worksheet gives
some information about what certain cells are supposed to do.
The DATES worksheet data (Birthdays and Anniversaries)
goes into the (WEEKS) columns K and N.
The HOLIDAYS worksheet data goes into the WEEKS columns J and M.

Can You figure out…
WHY do columns K and N show some data that should not be there?
Any assistance here would be greatly appreciated.
Thanks very much.
Mark5023
My2024 28.ods (305.3 KB)