Originally Posted by Fat Cereza
that's because shiny seeds with flawless IVs everywhere are not as common; increase the number of keep presses and keep looking on different dates. You can also increase the number of advancements.
To clarify on that last part, you should only be increasing the Shiny advancements over on the right of Time Finder (where the check box is for finding a nearby shiny--it only shows up when that box is checked). Unless you want
to be flailing around all day getting nothing and pestering us with needless questions, you need to keep the Min/Max IV frame to 1.