Why do the attackers say, “Woe to us, for the day declines”?

Battle would normally begin at daybreak and continue till evening. But these attackers are so impatient that they make a call to attack at noon. However, time is running out for the day declines, for the shadows of evening lengthen. So, the unusual decision is made to attack by night and destroy her palaces.¹ It is clear that this is an enemy that is supremely confident of victory and that Jerusalem will be overrun and destroyed.