This would all users to share links to the events in social media.

Since "real" wikipedia has no concept of a link to an individual event (they are just pages of wikitext), a scheme would need to be developed.

One option would be to create a link that would work for both web and the app by using a "#" and adding the year after the "#". This could be interpreted by the app correctly and on the web wold gracefully fallback to the date page on the web.

For example:
https://en.wikipedia.org/wiki/August_7#2008

Could be intercepted by the app to open the event from 2008 on August 7 in the app. But on the web would just open:
https://en.wikipedia.org/wiki/August_7

If more than one event exists for a year, they can be numbered like so:
https://en.wikipedia.org/wiki/August_7#2008-1