oneThis plural form is used for numbers like: 1
In %1$d hour
otherThis plural form is used for numbers like: everything else
In %1$d hours
In %1$d Stunde
In %1$d Stunden
In %1$d hour
In %1$d hours
In %1$d hour
In %1$d hours
In %1$d Stunde
In %1$d Stunden
%1$d - number of hours, %1$d may be skipped for singular if translation looks better.