|I think it's simple to do|
In actual DOS the OS you booted into, (not the Command Prompt, which you're probably referring to), you had to use a third party program. DOS came with a debugger you could use to write this program yourself.
The 32-bit versions of Windows (with Command Prompt) have a 16-bit support layer you could use, so you might still be able to do that.
The 64-bit versions (with Command Prompt) however eschew this 16-bit support layer (because we really need to move past the 1980's).
I would suggest picking up a script language with proper date support, such as VBScript or PowerShell.
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