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Well. Not sure about the 4-5 days.
But the 14 days option is for people who wants to promote something - Either a Project, Job Position etc.
Not everybody is just promoting their posts to get likes ;)

gotcha, right, good point, thanks 👍🏽

Been wondering the same thing, but I don't really use that feature so...

That's a valid point I haven't seen yet 😊.

It could be just marketing something. Otherwise, if voting is the target 🎯, then 7 days is enough