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

This turned out way more complex then I first suspected, and I guess that's what intrigued me, I searched every where and all the methods given wouldnt work on Windows 7.

So I have an alternate solution which uses a Visual Basic Script.

The batch creates and executes the script(DayOfWeek.vbs), assigns the scripts output (Monday, Tuesday etc) to a variable (dow), the variable is then checked and another variable (dpwnum) assigned with the days number, afterwards the VBS is deleted hope it helps:

@echo off

REM Create VBS that will get day of week in same directory as batch
echo wscript.echo WeekdayName(Weekday(Date))>>DayOfWeek.vbs

REM Cycle through output to get day of week i.e monday,tuesday etc
for /f "delims=" %%a in ('cscript /nologo DayOfWeek.vbs') do @set dow=%%a

REM delete vbs
del DayOfWeek.vbs

REM Used for testing outputs days name
echo %dow%

REM Case of the days name is important must have a capital letter at start
REM Check days name and assign value depending
IF %dow%==Monday set downum=0
IF %dow%==Tuesday set downum=1
IF %dow%==Wednesday set downum=2
IF %dow%==Thursday set downum=3
IF %dow%==Friday set downum=4
IF %dow%==Saturday set downum=5
IF %dow%==Sunday set downum=6

REM print the days number 0-mon,1-tue ... 6-sun
echo %downum%

REM set a file name using day of week number
set myfile=%downum%.bak

echo %myfile%

pause
exit

EDIT:

Though I turned to VBS, It can be done in pure batch, took me a while to get it working and a lot of searching lol, but this seems to work:

 @echo off
SETLOCAL enabledelayedexpansion
SET /a count=0
FOR /F "skip=1" %%D IN ('wmic path win32_localtime get dayofweek') DO (
    if "!count!" GTR "0" GOTO next
    set dow=%%D
    SET /a count+=1
)
:next
echo %dow%
pause

The only caveat for you on the above batch is that its day of weeks are from 1-7 and not 0-6