This article presents an overview of the literature on daily fluctuations in work engagement. Daily work engagement is a state of vigor, dedication, and absorption that is predictive of important organizational outcomes, including job performance. After briefly discussing enduring work engagement, the advantages of diary research are discussed, as well as the concept and measurement of daily work engagement. The research evidence shows that fluctuations in work engagement are a function of the changes in daily job and personal resources. Particularly on the days that employees have access to many resources, they are able to cope well with their daily job demands (e.g., work pressure, negative events), and likely interpret these demands as challenges. Furthermore, the literature review shows that on the days employees have sufficient levels of job control, they proactively try to optimize their work environment in order to stay engaged. This proactive behavior is called job crafting and predicts momentary and daily work engagement. An important additional finding is that daily engagement has a reciprocal relationship with daily recovery. On the days employees recover well, they feel more engaged; and engagement during the day is predictive of subsequent recovery. Finding the daily balance between engagement while at work and detachment while at home seems the key to enduring work engagement.
