How to delete log file after zipping in batch

Question

    
    **please check my code ... and suggest any changes to be made ... i m able to zipp the logs but not able to delete those logs.........
        thanking you...
        this is my code....
        @echo off
        set zip="C:\Program Files\7-Zip\7z.exe"
        rem Findout Month, Year and Date
        FOR /F "tokens=1,2,3,4 delims=/ " %%A in ('Date /t') do set year=%%D
        FOR /F "tokens=1,2,3,4 delims=/ " %%A in ('Date /t') do set month=%%B
        FOR /F "tokens=1,2,3,4 delims=/ " %%A in ('Date /t') do set day=%%C
        rem Solve problem Year start and adding 0 in month
        if %month% EQU 01 (
        set month=12
        set /a year=%year%-1
        ) else (
        set /a month=%month%-1
        if %month% LSS 10 set month=0%month%
        rem Set file names for last month file.
        set lastmonthfiles=server.log.%year%-%month%-
        %zip% -tzip  a -y "%lastmonthfiles%.zip" %lastmonthfiles%*
        if exist %lastmonthfiles%.zip(
        DEL server.log.%year%-%month%-*
        ) else (
            echo file not found
            pause

Answer 1

Actually it is only the 7Z filemanager that can delete files using the "Move" command and the "Delete after archiving" option.
if EXIST %lastmonthfiles%.zip ( DEL server.log.%year%-%month%-* ) ELSE echo zip not found
¯\_(ツ)_/¯