Nirmakumar answer is wrong. Date fields are always stored as UTC in the database. See the documentation here: https://docs.mendix.com/refguide/date-and-time-handling#1-introduction
If you always want to have the English format retrieve a user with that language in a microflow and use the community commons executeMicroflowAsUser to run the microflow you want to run in the English language. I would create a specific account for that so you can always retrieve it when needing translated data.
If you switch off the localize for the date field, then it will save in UTC format in the database. Mendix automatically takes care of transforming the dates to the localized dates when rendering on the browsers, which is also documented some where. If I am able to find the link, I can share you.
So, with the localize being switched off, you will have UTC dates stored in database. So, probably when exporting the data, you have some converters to localize the date or check if it already localized by Mendix.