oneCette forme plurielle est utilisée pour les nombres comme : 1
Repeat every %1$d month, on %2$s day of month
otherCette forme plurielle est utilisée pour les nombres comme : everything else
Repeat every %1$d months, on %2$s day of month
repeat_every_n_months
Repeat every %1$d month, on %2$s day of month
Repeat every %1$d months, on %2$s day of month
Repeat every %1$d month, on %2$s day of month
Repeat every %1$d months, on %2$s day of month
%1$d - number, %1$d may be skipped for singular if translation looks better.
%2$s - day of month. In English it's in ordinal form (1st, 2nd, 3rd...). In other languages it is just a number (1, 2, 3...).
If your language needs ordinal form to look better, please contact us directly
or provide appropriate comment with @FulmineSoftware at the beginning. We'll add then appropriate form in our app's code.