There is a better way to handle this, and it does not involve digging through your system settings. The Reddit user's frustration is entirely justified: Excel routinely overrides the formatting of imported data, swapping periods for commas and flipping month-day-year into day-month-year, all because your operating system is set to a German locale. The official advice, change your entire system region, is a sledgehammer for a screw. It assumes you want every application to behave the same way, which is rarely true when you collaborate across borders.
This is not a minor inconvenience. For anyone who regularly pulls US-format data into a German-localized machine, every copy-paste becomes a manual correction loop. You paste a column of dates, they shift into a format your design software cannot read, and you spend ten minutes reformatting cells or writing workarounds. The user's question, "Can I stop this?", deserves a straightforward answer, not a workaround that breaks other parts of your workflow. The solution exists: Excel has a per-workbook option to ignore the system locale when opening files. It is buried in File > Options > Advanced > "When calculating this workbook," but it is there. You can also use Power Query to import data with explicit format rules, bypassing Excel's automatic conversion entirely.
What this reveals is a deeper pattern. Legacy spreadsheet tools treat locale as a global setting because they were designed for a world where data stayed inside one country. That assumption is outdated. Modern teams share files across time zones, and the tool should respect the source format, not force its own. The user should not have to become a systems administrator to paste a column of dates. The product should adapt to the user's task, not the other way around.
The practical takeaway: stop letting your spreadsheet decide what your data looks like. If you work with US files on a German system, test the per-workbook locale option first. If that feels like too much digging, consider a tool that treats format as a property of the data, not the machine. The goal is not to eliminate formatting, it is to eliminate the friction between what you receive and what you need. That is a problem worth solving, and the solution starts with refusing to accept Excel's default behavior as inevitable.