Moon-Viewing Day is an annual event in Harvest Moon: Friends of Mineral Town and Harvest Moon: More Friends of Mineral Town. It is held on the 13th day of Fall, between 6:00 pm and 12:00 am, at the Summit of Mother's Hill.
On the night of Moon-Viewing Day, the moon is at its most beautiful. When the player enters the Summit of Mother's Hill, the girl/boy with the highest affection will be waiting at the overlook. The player will automatically give the dumplings to the girl/boy if they have one in their rucksack.
Even if you're married, the girl/boy with the high affection will still go meet you at the top of Mother's Hill. Don't expect the person who comes to meet you to always be your spouse!