Last modified: 2012-01-07 04:58:36 UTC
#time provides a way to format a date according to one's own wishes, but it uses the site language for output instead of the interface language. As link tables etc. don't seem to be a serious issue (e.g. on Bug 14404), I don't see why we should not deliver the localizable part in the user's interface language.
Link table coherence is an issue. Thus that we already have thing X doesn't mean that we want to add thing Y. This could be possible in (real) interface messages, but as I can see it it would change existing behaviour – that is not good. On the other hand we have already things which can change link table from parse to parse, for example the time related magic words. A whole separate issue is whether mixing content and user interface elements it a good idea.
Using the user's interface language would still cause lots of cache fragmentation. Marking WONTFIX.