Does variety increase happiness? Eight studies examine how the variety among the activities that fill people's day-to-day lives affects subsequent happiness. The studies demonstrate that whether variety increases or decreases happiness depends on the perceived duration of the time within which the activities occur. For longer time periods (like a day), variety does increase happiness. However, for shorter time periods (like an hour), variety instead decreases happiness. This reversal stems from people's sense of stimulation and productivity during that time. Whereas filling longer time periods with more varied activities makes the time feel more stimulating (which increases happiness), filling shorter time periods with more varied activities makes the time feel less productive (which decreases happiness). These effects are robust across actual and perceived variety, actual and perceived time duration, and multiple types of activities (work and leisure, self-selected and imposed, social and solo). Together the findings confirm that “variety is the spice of life”—but not of an hour.