A defining feature of biculturalism is the experience of switching back and forth between different cultural ways of being and acting in the world. This work investigates antecedents of this switching process using a cultural adaptation of the Day Reconstruction Method, in which participants divide the previous day into episodes and then rate these episodes on various criteria. We hypothesized that episode characteristics (specifically, language used) and stable personal dispositions (specifically, mainstream and heritage cultural orientations) would independently and interactively predict migrants’ cultural identification during an episode. We examined three types of identification among Russian-speaking migrants to Canada (N = 109): mainstream (“Canadian”); heritage (“Russian”); and mainstream–heritage hybrid (“Russian-Canadian”). Results of multilevel regression analyses supported our hypotheses overall. A more positive orientation to a given cultural group and the use of that group’s language(s) were associated with stronger identification with that group during an episode. Language Use × Cultural Orientation interactions were evident for heritage and hybrid situational identification. The positive association between heritage orientation and situational heritage identification was stronger during episodes when the heritage language was not used than when it was used. A positive heritage orientation was associated with greater situational hybrid identification only during episodes when a mainstream language was used. The results are consistent with the perspective that acculturation is a multifaceted, contextual, and dynamic process whereby people acquire and flexibly use multiple cultural repertoires to meet both their general goals and the cultural demands of specific situations.