web – Should end-users enter Dates or Numbers based on their browser locales vs based on the page content language?

I have a website for international users. Let’s say the website supports English users only ( All texts on the website are English words ). The website has a submit form that the end-users of the website need to enter Dates, Integers, and Decimals. At back-end side, I will convert all the text-based fields: Date, Integer, and Decimals to Date, Integer, Double objects.

My question is: What kind of Locale I should use to convert all text-based fields to Date, Integer, Double objects?

I have 2 choices: The first choice is I will always use US-Locale for the conversions. The second choice is I will use the end-user browsers setting locales (Request Locales).

If I use the first choice, let’s say the French, Japanese, … etc. users must always enter US Locale Date, Integer, Decimals formats.

If I use the second choice, the French users can enter French Locale Date, Integer, Decimals formats, the Japanese users can enter Japanese Locale Date, Integer, Decimals formats, … etc.

I know each of choice has its own pros an cons. but I would like to know which choice is recommended.

Thanks!