differences between in, on, at, for, during when describing a period of time

Question

I don't know which is the most proper preposition in the sentences below.

1. They eat a special dish during the first three days of the New Year.
2. They eat a special dish in the first three days of the New Year.
3. They eat a special dish for the first three days of the New Year.
4. They eat a special dish at the first three days of the New Year.
5. They eat a special dish on the first three days of the New Year.

I would like to mean that they cook a large quantity of dish before New Year, and eat it 9 times - 3 times of meals x 3days.

And can I construct the sentence like these:

• The dish is good for (helps) them during the busy first three days of the New Year because they don't need to cook if they have the dish.

• The dish is good for (helps) them in the busy first three days of the New Year because they don't need to cook if they have the dish.

• The same sentence with "at"

• The same sentence with "on"

Answer 1

"At" means a "Point in Time" ; not suitable to mean a "Period of Time".

"I went out at midnight"

"In" means ""At some time in a Duration" ; suitable to mean a "Period of Time".

"I will come back in July"

"On" means "At some time in a Duration" ; hence suitable.

"I came on Sunday"

"For" means "Extending, lasting" ; hence not suitable.

"We watch TV for hours"
"We ate for 3 Hours"

Using "for" in your case might mean that the ritual eating went on continuously for 3 Days !

"During" means "At some time in a Duration" ; hence suitable.

"During winter, it snows heavily"

You could also add the the word "Only" to mean that they eat nothing else.

During [ or In or On ] the first three days of the New Year, three times a Day, they eat only this special dish, which is cooked in large quantities to help avoid repeated cooking.

"During" is the best sounding here!