Setting a windows batch file variable to the day of the week

Question

I have a windows batch file that runs daily. Wish to log data into a file and want to rotate it (i.e. having at most the last 7 days worth of data).

Looked into the

Answer 1

@ECHO OFF
REM GET DAY OF WEEK VIA DATE TO JULIAN DAY NUMBER CONVERSION
REM ANTONIO PEREZ AYALA
REM GET MONTH, DAY, YEAR VALUES AND ELIMINATE LEFT ZEROS
FOR /F "TOKENS=1-3 DELIMS=/" %%A IN ("%DATE%") DO SET /A MM=10%%A %% 100, DD=10%%B %% 100, YY=%%C
REM CALCULATE JULIAN DAY NUMBER, THEN DAY OF WEEK
IF %MM% LSS 3 SET /A MM+=12, YY-=1
SET /A A=YY/100, B=A/4, C=2-A+B, E=36525*(YY+4716)/100, F=306*(MM+1)/10, JDN=C+DD+E+F-1524
SET /A DOW=(JDN+1)%%7

DOW is 0 for Sunday, 1 for Monday, etc.