Remove (make safe) "single quote" character from date string (which breaks JS)

When using Hebrew language in the course, Date strings inclue "Single Quote" chars just after the "Day" element in the Date format string. It breaks the JavaScript :-(

It might happen on other non English languages. so I am adding this safty check which remove the "Single Quote" char from the string.

Please code review, In case this hack needs to be applied elsewhere too.

Nadav :-)