This study examines the effect of election timing on electoral performance. Previous studies have indicated that incumbent governments opportunistically choose the timing of elections depending on business booms; that is, they politically “surf” over periods of strong economic performance. Recent studies have revealed that opportunistic election timing generates electoral benefits for incumbent governments. However, they have not taken into account how economic conditions affect the incumbent’s electoral performance in a snap election. Moreover, other studies have noted that incumbent governments call elections when they have high approval ratings. However, few studies have discussed whether incumbent governments attribute more importance to their approval ratings or economic conditions when determining election timing. Therefore, within the contexts of approval ratings and economic situation, this study examines the effect of election timing on electoral performance. In particular, I show (1) how calling elections during high approval ratings for the incumbent government and (2) how calling elections during business booms affects the incumbent government’s vote share through an analysis of Japanese electoral data.