Access to daylight plays important role in the design of good indoor environment. There are several methods for evaluation of interior daylighting based on the photometry and penetration of skylight and sunlight in buildings through apertures under specific situations or on the evaluation of the annual daylight climate. Effective utilization of daylight considering visual task performance and building time operation is studied scarcely. This book is text of the PhD. Thesis of Dipl. Ing. Maria Ferencikova, PhD. and extended by her supervisor Associate Professor Stanislav Darula. The book presents results of daylighting availability research carried out in Bratislava, offers new findings how to effectively utilize daylight in schools and nurseries, offices and hospitals during their operating time. Concept of the used methodology follows the EN 17037 idea of the daylighting evaluation while new found statistical characteristics allows to more sensitive and effective utilize naturallight in building interiors. This book is addressed to architects, illuminating engineers, students, profesionals interesting in daylighting design and standardization of daylighting in buildings.