oneThis plural form is used for numbers like: 1
Every %1$d week
otherThis plural form is used for numbers like: everything else
Every %1$d weeks
Každý %1$d týden
Každý %1$d týdny
Každý %1$d týdny
Every %1$d week
Every %1$d weeks
Every %1$d week
Every %1$d weeks
Každý %1$d týden
Každý %1$d týdny
Každý %1$d týdny
%1$d - number, %1$d may be skipped for singular if translation looks better.