@echo off setlocal enableextensions enabledelayedexpansion for /f %%v in ('set _ 2^>nul') do set "%%v=" set "p=((X)+((X)/4)-((X)/100)+((X)/400))%%7" (for /l %%i in (2000,1,2100) do ( set /a "func=^!(!p:X=%%i!-4) | ^!(!p:X=%%i-1!-3)" if !func! equ 1 set /p=%%i ))