How to compare today's date with a file's last modification date without regional settings influence?

It is possible to get the current date on a Windows system and the last modification date of a file, like thise:

• Current date : date /T
• Last modification date : ±echo %~tI% (where %I is the file within a FOR loop)

Both however depend on regional settings, so they need to be replaced by something else:

• Current date : wmic os get localdatetime
• Last modification date : ???

Does somebody know how to fill in the question marks?

Background information, the idea is to get a result like the following:

• Current date : 20170323115047.782000+060
• Last modification date : 20170323120513.0123
  

Chop off the first eight characters (in order to get the day)

• Current date : 20170323
• Last modification date : 20170323

This makes it possible to see that the file has indeed been modified today.
I want to avoid regional settings in order to be sure of the amount of characters I need to chop off.

For timestamp comparisons, you could use forfiles to find files modified today. This solution is more graceful than chopping substrings off of WMI query results I think.

@echo off & setlocal

set "file=notes.txt"

forfiles /d +0 /m "%file%" >NUL 2>NUL && (
    echo %file% was modified today.
) || (
    for %%I in ("%file%") do echo %%~I was last modified %%~tI
)

forfiles /? in a cmd console for more info. The forfiles command exits 0 on match, 1 on no match, allowing the use of conditional execution. Also, see this related question.