As you have probably seen yourself, it is not a HJ tinnie but a tinnie from "Studentenbund". I have found some information about these "Studententage" - see below.
German Student Days 1919–1945
In the Weimar Republic and the Third Reich, the annual general meetings of the then umbrella organization Deutsche Studentenschaft were referred to as the German Student Day. This practice goes back to historical models such as the Landtag or Reichstag and is still common today in a similar form in other professional organizations (e.g. the German Medical Association).
The 1st German Student Day took place from 17.-19. 1919 in Würzburg, on the occasion of which the German student body was founded. Further student days took place there in 1922 and 1923 as well as from 22.-27. May 1939.[2][3] The 4th German Student Day in Erlangen in 1921 was of particular importance: it concluded the Erlangen program, in which both the term working student was coined and the foundation for the development of today's student unions was laid.
At the 14th German Student Day in Graz in 1931, a National Socialist was elected to head the German student body for the first time. In the period that followed, the German Student Days lost their function as the democratic decision-making body of the student body and, like the Nazi Party Rallies, became mere propaganda events. Instead, at the behest of the Reich student leadership, annual "student days" with political rallies and sporting competitions were held in all university towns from 1938.
Hope you enjoy this information
Michael