This paper analyses the activities of Andrey Monastyrsky, the leader of the group called “Collective Actions” (CA) which is a part of Moscow conceptualism, namely, a remarkable community of Soviet unofficial art in the 1970s and 1980s. CA is a group that has practiced many performances (they call it “action”) in the field and the forest near Moscow since 1976. The perspective which could be the key to re-examine their long history is the issue of how they sought to appropriate and privatize spacetime. Regarding the privatization, Boris Groys, Russian art-critic and philosopher, pointed out that this term is linked to Moscow conceptualism, though his argument is mainly related to another group from a younger generation of conceptualism. Meanwhile, it is researcher Octavian Esanu who mentions the problem of space and time in CA. However, there exists scope for further research on the theme of time based on the perspective of appropriation. Therefore, this paper tried to shed light on Monastyrskyʼs awareness of the issue about time above all. Specifically, a comparative review of Monastyrskyʼs twin diary-novels (“Kashirckoe Shosse” written in 1987 and “Maintenance work of Kashirskoe Shosse” written in 2009) was conducted in this paper. As a result, it turns out that Monastyrsky, who was absorbed in an eternal metaphysical world in “Kashirskoe Shosse,” began to be desperately aware of the systematic passage of time, i.e., a concept in opposition to his sense of an eternity in “Maintenance work.” It should be noted, however, that in this instance, the passage of time dominates his consciousness as a certain type of god and he invokes the words of Buddhism to keep a proper distance from this new absolute being. In other words, he has struggled against the temptation to the metaphysical in another world in “Kashirskoe Shosse,” and against the gravity of the passage of time in “Maintenance work.” Recent actions of the CA might be regarded as the results of such an attempt. In some actions of the CA, obsession about dominative time and the metaphysical world disappeared and the conception of transcendence itself was transformed. There occurred a rearrangement of the past and the construction of private spacetime through the appropriation of the absolute thing, which can be regarded as one of the distinctive strategies of CAʼs activity.