As a user of the watchlist expiry feature I [1] would like to watch articles I edit for six months.

Currently there is a preference checkbox to Automatically watch articles I edit, but that adds an indefinite watch.

[1] not me personally, lodging this ticket on behalf of another user, see https://en.wikipedia.org/wiki/Wikipedia:Teahouse#Automatically_watching_articles_I_edit_for_six_months