Time is regarded as the immanent dimension for the social experience. This phenomenologically informed perspective of time is built into the ethnomethodological programme jointly proposed by Garfinkel and Sacks as they set out to uncover social orders through examining the temporal sequence in practical activity. However, Garfinkel and Sacks took different paths from this initial proposal in their separate development of Ethnomethodological Studies of Work and Conversation Analysis. Focusing on different forms of data, the two programmes adopted different approaches to time and action in constructing the time structures in their sociological description of activity. However, the difference has seldom been subjected to discussion and much less attempt to explore a possible synthesis of the two programmes from there. This article attempts to address this gap by proposing a perspective of multi-layered temporality in social interaction. The analysis examines three extracts from a university communication workshop for students and explicates different modes of how simultaneous sequences can constitute participants’ action in situ: (1) simultaneous sequences by different actors; (2) simultaneous sequences by the same actor; (3) simultaneous sequences within a participatory framework. Contending the social actors’ phenomenological potential to perceive simultaneous sequences in different time frames, we conclude that the ‘situational time’ in EM and ‘conversational time’ in CA can be commensurable. Interweaving different layers of temporality into an ethnomethodological description, practitioners can better reconstruct a ‘reasonable total picture’ of social activity to manifest its complex, seen-but-unnoticed endogenous social order. Beyond ethnomethodology, the multi-layered perspective of time provides the basis for a holistic approach to time, allowing the enquiry of broader social time through studying social life in vivo.