Background Paragraph: Alberta's electrical demand varies throughout the day and across the seasons. When individuals are fixing supper and using home appliances, demand for power goes up, as it does during heat waves and cold snaps. It tapers off during spring and fall. Like other mechanical devices, generators fail from time to time. If they are wind-powered, their output varies with the wind. 
Story: It has been a weird week in the neighborhood. On Monday, there was a heat wave. On Tuesday, a cold snap happened. On Wednesday, everybody was using their ovens to bake cakes for the contest. On Thursday, everybody stayed home to do nothing but pray. On Friday, everybody went to the park to play in a soccer tournament and sleep in tents . On Saturday, there was another heat wave. On Sunday, another cold snap happened. 
Question: What day did demand for power go up: Sunday or Friday?
Sunday.