Some may disgaree but I am pretty comfortable saying there are no certainties around this.
Generally, a bigger beer needs more time than a smaller one, as does one with more complexity or more ingredients.
I make 1.050-60 beers that are GREAT after 2 weeks in the keg, sometimes after 3 days. Sometimes they peak after several months (My brown ales and stouts seem best then), and sometimes they turn crappy and dull after 2-3 months (my last blonde recipe).
If you made a 1.090 IIPA, it would probably be fine within 1 week of kegging, and 3 weeks or so in bottles. However, if you made a 1.090 Russian Imperial Stout or Barleywine, 4-6 months is probably more like it to let the flavours balance better.
Sometimes people make cloudy beer and more time will also help clear them. This can have an impact not only in appearance, but also smell and taste, as yeast or trub is not without flavour.
