Everyday smartphone use gives rise to a new kind of user experience that is characterized by unplanned use. Exploring spontaneous uses promises to improve our understanding of both the deeper integration of the smartphone into mundane activities, as well as the smartphone's potential for distraction and interruption. Therefore, we studied the user experience of unplanned smartphone use to unpack its experience qualities. For capturing unplanned use from a first-person perspective, 36 participants each produced two hours of continuous video recordings with wearable cameras. The findings introduced the experience quality of 'timelessness,' a feeling that unplanned smartphone use is a series of unrelated moments, lacking a coherent sense of past, present, and future. Unplanned use usually leaves no memory of what it was, presents no attributes of what it is, and projects no endings of what it will be. The study contributes a theoretical framework of unplanned use for experience design.