Date picker not visible on SSRS report for some users on both Chrome and IE

We have a 365 CE organization, some users (around 3 users out of 50 users) has a strange issue. Date time parameters don't have a date picker displayed. The date fields are displayed as a normal text inputs. As you can see in the following screenshots:

We've tried to login with a different user on the same machine and using the same browser and the fields are displayed correctly:

Please note the following:

• Using a different user on the same machine and on the same browser, the picker is working fine and disabled with no issue.
• This on both browsers IE and Google Chrome. And both are working fine for different users.
• This is for all the reports not just one report.
• We tried to fill in the date manually, then we opened SQL Profile and we found out that, the date is passed to the SQL Server with wrong values than the values passed manually, like year 2000 and 2058 years.
• The organization was updated from 2011 organization and it is working fine for the same users on 2011.
• We didn't find any errors in the SSRS server or the Dynamics CRM server.
• We tried to give these users more permissions on the SSRS server on the reports folder and the same issue.
• We deleted the report and uploaded it again to the CRM and the same issue.
• We are using SQL Server and SSRS 2012 version.

So what we can do, is is a bug or what?!

Update:

The warnings displayed in the developer tools in the console panel:

Changing the language under user's personalized settings did the trick and solved the issue. The working users had Arabic(Egypt) language, whereas the users with the issue had Arabic (Saudi Arabia), because this is the language pack we installed. Changing the user language to Arabic Egypt solved the issue, I don't know why!