Correct localization in Modx when dealing with plurals?

Question

PHP

How to do localization in modx when working with plurals?
1, 21, 31… day
2, 3, 4… days
5, 6, 7… days
So far, just this snippet idea:

return (n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2)

and use inside the translation value:

By the way, there is selecta filter, but I have not tried it. Can it be used instead of a complex design?
Update :

Answer 1

The repository has the Units package - exactly what you need in this case.

Answer 2

If you need to display dates, it's easier to take a ready-made .
If you're not interested, you can look at the source .