The perihelion of the earth each year is just several days after Christmas Day (3 or 4 January). So,the distances from the earth to the sun and from the earth to the moon may reach the closest point around Christmas every 4.425 years.

• 而每年的地近日点(1月3日或4日)正置圣诞节过后几天；因此；日、月、地相对运动每隔4.；425a 在圣诞节前后三者距离总会达到最近。