key of/to the year

[Itasan]

Which is correct?
1. The New Year's Day is the key OF the year.
2. The New Year's Day is the key TO the year.
Is there any similar proverb in English?
Thank you.

[Casiopea]

Which is correct?
1. The New Year's Day is the key OF the year.
2. The New Year's Day is the key TO the year.
Is there any similar proverb in English?
Thank you.

There isn't a similar proverb in English, to my knowledge.

New Year's Day is the key to the year.
=> New Year's Day determines how the new year will unfold.

New Year's Day is the key of the year.
=> awkward, the best day of the year.

[Itasan]

Thank you very much, Casiopea, for the valuable information.
Itasan

[Casiopea]

You're most welcome.