This will change the name of the TEXT file with the current date.
@echo off
for /f "tokens=2 delims==" %%a in ('wmic OS Get localdatetime /value') do set "dt=%%a"
set "YYYY=%dt:~0,4%"
set "MM=%dt:~4,2%"
set "DD=%dt:~6,2%"
set "HH=%dt:~8,2%"
set "Min=%dt:~10,2%"
set "Sec=%dt:~12,2%"
set "datestamp=%YYYY%%MM%%DD%"
set "timestamp=%HH%%Min%%Sec%"
ping IPADDRESS >>"C:\path to log\%datestamp%.txt"