This paper explores time-related aspects of e-commerce and their impact on the environmental sustainability of last-mile deliveries. It addresses two key questions: 1) What time-related aspects of e-commerce can consumers encounter during an online purchase?, and 2) What implications can these time-related aspects of e-commerce have on the sustainability of last-mile deliveries? The study uses diary entries from 15 Swedish e-commerce consumers over one month, followed by semi-structured interviews. Findings reveal that consumers encounter various time-related factors throughout the purchasing process, from the website to delivery, with some of these factors having significant implications for the environmental sustainability of last-mile deliveries.