What influence does the time of day have upon the way the meeting in chapter 5 goes?

In chapter 4, the hunters, led by Jack, have killed a pig at last, but in doing so, they have neglected the signal fire, allowing it to go out just when a ship passed within sight of the island, thereby ruining their chance of rescue. Ralph is furious, but he is also "envious and resentful" of the attention Jack receives for killing the pig. He proclaims they must have a meeting, "even if we have to go on into the dark." This statement foreshadows that the meeting may not go well. In fact, having a meeting in the dark turns out to be counter-productive and sets up the first major crisis of leadership Ralph experiences.

The meeting starts out with Ralph forcefully laying down rules about labor, cleanliness, and keeping the fire going. About these things Ralph allows no discussion, and he squelches any laughter or opposition. However, by the time the topic of fear comes up, "what sunlight reached them was level," in other words, it is nearly sunset. This is the worst possible time of day to begin talking about fear, to the littluns especially. As Piggy is giving his big speech denying the validity of fear, "the sun had gone as if the light had been turned off."

Now, in the dark, a littlun comes forward and describes his recent nightmare and something he saw moving in the trees. That turns out to have been Simon, but then Percival comes forward. He begins to cry, and his sorrow is contagious, spreading to other littluns. Finally, Percival suggests the beast comes up from the sea, and "in a moment the platform was full of arguing, gesticulating shadows."

Then the subject of ghosts is brought up. Ralph states, "We ought to have left all this for daylight." The wind picks up, adding to the eerie atmosphere. Ralph admits he was wrong "to call this assembly so late," but instead of postponing the discussion until the morning, he takes a vote on ghosts, asking the question the worst possible way. Ralph has to strain into the darkness to see that many hands are raised in response to, "Who thinks there may be ghosts?"

Jack uses the cover of darkness to empower his rebellion against Ralph and the rules. In the bright sunshine, when things were more reasonable and controlled, he may not have dared opposing Ralph so directly, but with the children shuddering in fear and Ralph not providing proper leadership, Jack cries, "Bullocks to the rules!" and leads all the boys but Ralph, Piggy, and Simon away in a "discursive and random scatter."

This leads Ralph to lose confidence, and he laments, "I ought to give up being chief. Hear 'em." The entire meeting may have turned out much differently if it had been held in daylight. The darkness allowed the boys' fear to run amok and encouraged Jack to rebel against the rules and Ralph.