Are EVs gained on level-up, when used to calculate IVs, counted as a pre-level-up or post-level-up EV?

Question

So it's more like two questions in one.

First, for Gen 3 if I level up against a Poochyena, granting me +1 Attack EV, does the EV go to the level I was before leveling up, or to the level I leveled up to?

Second, I'm using this calculator (the only one my school doesn't have restricted... somehow): http://www.metalkid.info/Pokemon/Calculators/IV.aspx and everytime I input an EV, it also puts it on the columns for the next levels. So does that mean that to calculate my IVs when at Level 7 ,I must add the EVs obtained in levels 5 and 6?

Comments

For the first question, EVs don't go to levels. The stat calculating formula looks at how many EVs the Pokemon has in the stat. It doesn't matter whether the Pokemon gained those EVs at level 1, level 99, or anywhere in between.
I can't figure out why Metalkid's calculator has 5 different rows where you can enter EVs.

Answer 1

Q1)evs dont go towards levels they are their own thing that rack up and only lower with ev lowering berries so you would not need to add the evs from before you are lv 7 but instead the evs it currently has.
Q2)no you don't.
If your still stuck try these:
https://m.bulbapedia.bulbagarden.net/wiki/Individual_values
https://m.bulbapedia.bulbagarden.net/wiki/Effort_values