Proposed solution: In Special:Preferences#mw-prefsection-watchlist, under Watched pages, replace the checkboxes by dropdowns or radio buttons offering time periods alongside the existing No and Forever options. Apply these values when watchlisting pages silently, and preselect them as the defaults when watchlisting pages via a dialog such as that below the edit box.
More comments: Some of us occasionally manually watchlist a page of interest permanently, but more often want to watch pages we just edited for a week or month in case of replies, reversion, etc. This is particularly useful for gnomes who make many minor edits.
I wouldn't use this myself but I see a huge use case for it and find it odd that this was omitted from the implementation. — Bilorv (talk) 00:32, 2 December 2020 (UTC)[reply]
One more thing: if a page is already watched, the time period suggested should be the longer of the existing watch duration and the default. I'm not sure (and don't mind) exactly how this works with (say) 15 days of a 1 month watch left where the default is a week; leaving the existing watch period would be one good solution. Certes (talk) 16:42, 9 December 2020 (UTC)[reply]
Support It will be necessary for us to determine a specific deadline for all pages monitored, in addition to choosing them to leave the others for permanent time. WikiFermsg15:50, 9 December 2020 (UTC)[reply]