Windows Server bat deletes objects of a specified date

In windows, the forfiles command can be used to operate files based on the timestamp of files,
Forfiles /? You can view detailed help information.

FORFILES [/P pathname] [/M searchmask] [/S] [/C command] [/D [+ |-] {yyyy/MM/dd | dd}]
/P "directory name" specifies the search path
/S recursive search
/C "specify the command to be executed"
/D query at the specified time
+ Yyyy/MM/dd specifies the absolute time to find the file that is later than the specified date.

-Dd files earlier than the current time and n days earlier than the current time

Displays the files in the specified directory that have not been modified for more than 6 days. By default, the file name is output.
Forfiles/p "% bak_dir %"/S/D-6
Forfiles/p "% bak_dir %"/S/D-6-C "cmd/c echo @ file"

Complete output path

Forfiles/p "% bak_dir %"/S/D-6-C "cmd/c echo @ path"

Delete objects in the specified directory that have been last modified for more than 6 days

Forfiles/p "% bak_dir %"/S/D-6/C "cmd/c del/q @ file"

Bytes

If exist "c: \ Program Files \ winrar" set Path =; "c: \ Program Files \ winrar"; % SystemRoot % \ system32
If exist "c: \ Program Files (x86) \ winrar" set Path =; "c: \ Program Files (x86) \ winrar"; % SystemRoot % \ system32
Forfiles/p "% bak_dir %"/S/D-6/C "cmd/c rar.exe a backp.rar @ path"

Bat obtains the previous month.

@ Echo off
Setlocal EnableDelayedExpansion
Pause
Rem ################# obtain the date of the previous month ################## ######
Rem get year
Set year = % date :~ 0, 4%
Rem obtains the month.
Echo current year: % year %
Set mounth = % date :~ 5, 2%
Echo Current Month: % mounth %
Echo #####################
If "% mounth %" = "01 "(
Set/A year = % year %-1
Set/A lastmounth = 01
Echo current year: % year % _ % mounth %
Echo **************
) Else (
Rem minus one for the current month
Echo % mounth %
Set/A lastmounth =! Mounth! -1
Echo previous month :! Lastmounth!
Rem if the value of 1 in the current month is less than 10, then add it with zero, for example, 2 = 02.
If! Lastmounth! Lss 10 (
Set lastmounth =! Lastmounth!
 )
Echo last month: % year % _! Lastmounth!
)
Pause
Method 2

?
@ Echo off
Rem setlocal
Echo date: % date %
REM separation Year Month Day
@ Set year = % date :~ 0, 4%
Set month = % date :~ 5, 2%
Set day = % date :~ 8, 2%
Echo this year: % year %
Echo this month: % month %
Echo ############# test #################
If "% month %" = "01 "(
Set/A lastyear = % year %-1
Echo last year: % lastyear %
Set lastmonth = 12
Echo last month: % lastmonth %
Echo last year_month: % lastyear % _ % lastmonth %
Echo ############ month = 01 #############
) Else (
If "% month %" = "02" set lastmonth = 01
If "% month %" = "03" set lastmonth = 02
If "% month %" = "04" set lastmonth = 03
If "% month %" = "05" set lastmonth = 04
If "% month %" = "06" set lastmonth = 05
If "% month %" = "07" set lastmonth = 06
If "% month %" = "08" set lastmonth = 07
If "% month %" = "09" set lastmonth = 08
If "% month %" = "10" set lastmonth = 09
If "% month %" = "11" set lastmonth = 10
If "% month %" = "12" set lastmonth = 11
Echo last year_month: % year % _ % lastmonth %
Echo ############## month! = 01 ##############
)
Pause