I have had a few complaints and observations based upon your example. This issue has been escalated to Microfocus and this is there explanation and response to this issue:
"As you pointed correctly, previous ALM versions did not have this feature, we asked R&D last month the reasons for this change in ALM 15.0.1 version and we asked if it was a defect, the response was that this is by design in ALM 15.0.1, Developers had in 15.0.1 a new enhancement to append the date format (add that piece of text), basically it was required by some other customers, because they have different client machines in different locales with different date format.
Since this was added to ALM code source for this latest ALM version and a feature recently added based on other customer’s needs, we asked R&D the possibilities to remove it because certainly we have receive the same request from different companies during these weeks. Developers are not planning to remove it immediately (for example in next patch release), however they are willing to help us to evaluate the possibility to add a parameter in order to enable or disable the feature. This parameter is the reason about why the ER was opened/created, we (Support Team) have the possibility to link Orasi (PARTNER 2nd Level Support) with the Enhancement Request internally (I am doing it now internally), we are linking the request with each customer that are asking us for this functionality to be removed, this will allow us to share the expectation and perspective from customers and get more attention from ALM PM/FA"
As you can see this is a change administered by R&D and others have asked to remove this mask as well so it is being address in the future possibly as so many have reacted towards this change asking it to be removed.
Hope this helps,