We use experience sampling methodology and adopt the integrative needs model of crafting to investigate employees' daily energy trajectories, and to test whether employees' energy can be conserved or increased throughout the day through the proactive behavioral strategy of needs-based crafting. We first examine the daily trajectories of energy and then investigate the role of employees' daily crafting efforts (at work and in their private lives) in managing their energy throughout the day. Finally, we explore the daily within-person trajectories of needs-based crafting. We tested our hypotheses on a sample of 110 employees providing data on four nonconsecutive days (resulting in 2,358 observations nested in 396 days). Continuous growth curve analyses confirmed that energy follows an inverted U-shaped pattern of increasing energy until noon, after which energy steadily decreased until bedtime. However, daily crafting efforts contributed to these change trajectories: On days when employees crafted more than average, their energy was higher, particularly in the morning and afternoon. These positive crafting effects disappeared toward the end of the day, before bedtime. Crafting followed a linear trajectory, increasing over the course of the day, suggesting that it is a proactive strategy people also engage in outside of work. This suggests that domain-spanning needs-based crafting could be an important proactive strategy to maintain higher energy throughout an entire working day, even in the afternoon, when energy normally starts to fall. Our research contributes to our understanding of the nature of energy and of the microdynamic, within-person energy effects of general crafting efforts.