Question: Osechi-ryōri, are traditional food,started in the Heian Period (794-1185), sometimes used to celebrate which annual festival with its own customs?
Sentence (from "Japanese New Year"): Since 1873, the official Japanese New Year has been celebrated according to the Gregorian calendar, on January 1 of each year, New Year's Day (元日 , Ganjitsu ) .
Relevant evidence: No