def get_oriental_zodiac_of_year_number(oriental_zodiac_date_time)
oriental_zodiac_date_time \
= oriental_zodiac_date_time.change_offset_to_japan(oriental_zodiac_date_time)
target_year = oriental_zodiac_date_time.year
rissyun_date_time = \
AlmanacSolarTerm.new.get_sekki_date_time(oriental_zodiac_date_time.year, \
oriental_zodiac_date_time.offset, \
0)
if 1 == oriental_zodiac_date_time.month
target_year -= 1
end
if 2 == oriental_zodiac_date_time.month && \
rissyun_date_time.day > oriental_zodiac_date_time.day
target_year -= 1
end
oriental_zodiac_of_year_number = (target_year % 60) - 3
if 0 > oriental_zodiac_of_year_number
oriental_zodiac_of_year_number += 60
end
return oriental_zodiac_of_year_number
end