windows batch file get few days ago

using vbs,  get parameter from Wscript.Arguments.Item(0)

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d = date() - Wscript.Arguments.Item(0)
wscript.echo year(d) * 10000 + month(d) * 100 + day(d)

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execute it with cscript //nologo

example for date of 3 days ago.
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@echo off
for /f %%a in ('cscript //nologo daysago.vbs 3') do set mydate=%%a
echo %mydate%

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