early spring; beginning of spring
Refers to the very start of spring, often with a poetic or seasonal nuance. Can be used in both literal and literary contexts.
The wind of early spring is still cold.
New Year; New Year's
Specifically refers to the New Year period, often used in seasonal greetings or traditional contexts. More literary than 正月.
I wish you a happy New Year.
初春に咲く花を探しに行こう。
Let's go look for flowers that bloom in early spring.
It was a bright day fitting for the New Year.
Compound of 初 (hatsu, 'first') + 春 (haru, 'spring'). The New Year sense arises from the traditional lunar calendar, where the new year coincided with the beginning of spring.