Setting a windows batch file variable to the day o

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 commands DATE and DELIMS - Cannot figure out a solution.

Is there a simple solution to create a file name that contains the day of the week i.e. 0 for monday etc.

Or do I have to resort to some better shell script.

Answer 1

First - Copy CON SETUPDAY.001 SET WORKDAY=^Z (very important - no cr/lf)

DATE /T >SETUPDAY.002
COPY SETUPDAY.001+SETUPDAY.002 NEWDAY.BAT >nul
CALL NEWDAY.BAT

SET WEEKDAY=%WORKDAY:~0,3%
SET MDY=%WORKDAY:~4,10%

USE %WEEKDAY% IN YOUR SCRIPT

Answer 2

I thought that my first answer gives the correct day of week as a number between 0 and 6. However, because you had not indicated why this answer does not give the result you want, I can only guess the reason.

The Batch file below create a log file each day with a digit in the name, 0=Sunday, 1=Monday, etc... The program assume that echo %date% show the date in MM/DD/YYYY format; if this is not the case, just change the position of mm and dd variables in the for command.

@echo off
for /F "tokens=1-3 delims=/" %%a in ("%date%") do set /A mm=10%%a %% 100, dd=10%%b %% 100, yy=%%c
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, dow=(c+dd+e+f-1523)%%7
echo Today log data > Day-%dow%.txt

If this is not what you want, please indicate the problem so I can fix it.

EDIT: The version below get date parts independent of locale settings:

@echo off
for /F "skip=1 tokens=2-4 delims=(-/)" %%A in ('date ^< NUL') do (
   for /F "tokens=1-3 delims=/" %%a in ("%date%") do (
      set %%A=%%a
      set %%B=%%b
      set %%C=%%c
   )
)
set /A mm=10%mm% %% 100, dd=10%dd% %% 100
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, 

dow=(c+dd+e+f-1523)%%7
echo Today log data > Day-%dow%.txt

EDIT: The version below insert day of week as 3-letter short name:

@echo off
for /F "skip=1 tokens=2-4 delims=(-/)" %%A in ('date ^< NUL') do (
   for /F "tokens=1-3 delims=/" %%a in ("%date%") do (
      set %%A=%%a
      set %%B=%%b
      set %%C=%%c
   )
)
set /A mm=10%mm% %% 100, dd=10%dd% %% 100
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, 

dow=(c+dd+e+f-1523)%%7 + 1
for /F "tokens=%dow%" %%a in ("Sun Mon Tue Wed Thu Fri Sat") do set dow=%%a
echo Today log data > Day-%dow%.txt

Regards,

Antonio

Answer 3

If you can change format of short date in the PC to "ddd yyyy-MM-dd" (only first parameter 'ddd' is compulsory), then following command returns-

c:\>vol | date
The current date is: Mon 2014-12-01

Then you can write you batch file -

@echo off

vol | date | find /i "sun" > nul 
if not errorlevel 1 goto SUN

vol | date | find /i "mon" > nul 
if not errorlevel 1 goto MON

      # write block for other week days    

goto END

:SUN
set fname="sun"
goto BACKUP

:MON
set fname="mon"
goto BACKUP

      # write block for other week days

:BACKUP
echo %fname%

:END

Answer 4

Another spin on this topic. The below script displays a few days around the current, with day-of-week prefix.

At the core is the standalone :dpack routine that encodes the date into a value whose modulo 7 reveals the day-of-week per ISO 8601 standards (Mon == 0). Also provided is :dunpk which is the inverse function:

@echo off& setlocal enabledelayedexpansion
rem 10/23/2018 daydate.bat: Most recent version at paulhoule.com/daydate
rem Example of date manipulation within a .BAT file.
rem This is accomplished by first packing the date into a single number.
rem This demo .bat displays dates surrounding the current date, prefixed
rem with the day-of-week.

set days=0Mon1Tue2Wed3Thu4Fri5Sat6Sun
call :dgetl y m d
call :dpack p %y% %m% %d%
for /l %%o in (-3,1,3) do (
  set /a od=p+%%o
  call :dunpk y m d !od!
  set /a dow=od%%7
  for %%d in (!dow!) do set day=!days:*%%d=!& set day=!day:~,3!
  echo !day! !y! !m! !d!
)
exit /b


rem gets local date returning year month day as separate variables
rem in: %1 %2 %3=var names for returned year month day
:dgetl
setlocal& set "z="
for /f "skip=1" %%a in ('wmic os get localdatetime') do set z=!z!%%a
set /a y=%z:~0,4%, m=1%z:~4,2% %%100, d=1%z:~6,2% %%100
endlocal& set /a %1=%y%, %2=%m%, %3=%d%& exit /b


rem packs date (y,m,d) into count of days since 1/1/1 (0..n)
rem in: %1=return var name, %2= y (1..n), %3=m (1..12), %4=d (1..31)
rem out: set %1= days since 1/1/1 (modulo 7 is weekday, Mon= 0)
:dpack
setlocal enabledelayedexpansion
set mtb=xxx  0 31 59 90120151181212243273304334& set /a r=%3*3
set /a t=%2-(12-%3)/10, r=365*(%2-1)+%4+!mtb:~%r%,3!+t/4-(t/100-t/400)-1
endlocal& set %1=%r%& exit /b


rem inverse of date packer
rem in: %1 %2 %3=var names for returned year month day
rem %4= packed date (large decimal number, eg 736989)
:dunpk
setlocal& set /a y=%4+366, y+=y/146097*3+(y%%146097-60)/36524
set /a y+=y/1461*3+(y%%1461-60)/365, d=y%%366+1, y/=366
set e=31 60 91 121 152 182 213 244 274 305 335
set m=1& for %%x in (%e%) do if %d% gtr %%x set /a m+=1, d=%d%-%%x
endlocal& set /a %1=%y%, %2=%m%, %3=%d%& exit /b

Answer 5

%DATE% is not your friend. Because the %DATE% environment variable (and the DATE command) returns the current date using the Windows short date format that is fully and endlessly customizable. One user may configure the system to return 07/06/2012 while another might choose Fri060712. Using %DATE% is a complete nightmare for a BAT programmer.

There are two possible approaches to solve this problem:

1. You may be tempted to temporarily change the short date format, by changing the locale settings in the registry value HKCU\Control Panel\International\sShortDate, to your recognizable format. Then access %DATE% to get the date in the format you want; and finally restore the format back to the original user format. Something like this

   reg copy "HKCU\Control Panel\International" "HKCU\Control Panel\International-Temp" /f >nul
   reg add "HKCU\Control Panel\International" /v sShortDate /d "ddd" /f >nul
   set DOW=%DATE%
   reg copy "HKCU\Control Panel\International-Temp" "HKCU\Control Panel\International" /f >nul
   

   but this method has two problems:

   • it tampers with a global registry value for its local particular purpouses, so it may interfere with other processes or user tasks that at the very same time query the date in short date format, including itself if run simultaneously.

   • and it returns the three letter day of the week in the local language that may be different in different systems or different users.

2. use WMIC Win32_LocalTime, that returns the date in a convenient way to directly parse it with a FOR command.

   FOR /F "skip=1" %%A IN ('WMIC Path Win32_LocalTime Get DayOfWeek' ) DO (
     set DOW=%%A
   )
   

   this is the method I recommend.

Answer 6

I have this solution working for me:

Create a file named dayOfWeek.vbs in the same dir where the cmd file will go.

dayOfWeek.vbs contains a single line:

wscript.stdout.write weekdayname(weekday(date))

or, if you want day number instead of name:

wscript.stdout.write weekday(date)

The cmd file will have this line:

For /F %%A In ('CScript dayOfWeek.vbs //NoLogo') Do Set dayName=%%A

Now you can use variable dayName like:

robocopy c:\inetpub \\DCStorage1\Share1\WebServer\InetPub_%dayName% /S /XD history logs