This is the 17053rd most frequent Russian word.
спокойного
"Спокойного" means "calm" or "peaceful" in English.
The word 'спокойного' is used as an adjective in the genitive case, modifying 'вечера' (evening), indicating a wish for calm and tranquility.
Желаю вам спокойного вечера.
I wish you a peaceful evening.
Here 'спокойного' functions attributively in the genitive case, referring to the act of decision-making ('принятия решений') needing calmness and quiet.
В данной ситуации важны спокойного принятия решений.
In this situation, calm decision-making is important.
In this sentence, 'спокойного' modifies 'очарования' (charm) in the genitive case, describing the type of charm as calm or tranquil.