When you are changing users language from UK_GB to US at Users Settings -> Profile, date format is not changed. UK date`s format is like d-m-Y, and US - m/d/Y.

Steps to reproduce:

1. Validate, that date format for UK_GB is displayed correctly according to UK_GB time format(d-m-Y)
2. Change Users language from UK_GB to US at Users Settings -> Profile
3. Validate date`s format

Expected result: Date format should be displayed correctly according to US time format(m/d/Y).
*Actual result: * Date format is still displayed according to UK_GB locale