一月一日から一月七日、または一月十五日まで、新しい年のお祝いをします。
I would understand this sentence if the part in bold was omitted: New Year is celebrated from January 1 to January 15. What is "一月七日、または” for?
Japanese Language Stack Exchange is a question and answer site for students, teachers, and linguists wanting to discuss the finer points of the Japanese language. It only takes a minute to sign up.
Sign up to join this communityまたは
means or
.
So, the sentence means New Year is celebrated from January 1 to January 7 or January 15.
一月一日から一月七日、または一月十五日まで、新しい年のお祝いをします。
Other examples:
アメリカ、または日本に行きます。
I'll go to the US, or Japan.
このテストはスミス先生、またはジョンソン先生に渡してください。
Please hand this test to Smith-sensei, or Johnson-sensei.