The present study aims to analyse an expression that the blessed Carmelite Elizabeth of the Trinity uses – both in Heaven on Earth, and in the Final Retreat – to define time, the exact origin of which is unknown. Following an introduction in which the problem of temporality is placed within the context and rhythm of her spiritual experience, the traditional frame of reference is called upon in relation to this problem, particularly emphasising the platonic (or neo-platonic) paradigms that influenced the conception reflected by the mystic current. In the second part there is a discussion of the notion of eternity – of ‘eternity begun’ implied in Elizabeth of the Trinity and oscillating between the sense of temporal continuity or its annulment. Afterwards there is a consideration of the differential conjugation of the sense of an eternal ‘progress’ or rather of an interpretation of time as recurrence of a perpetual state. It concludes with this ‘third’ dimension of time, neither heavenly nor eternal, nor of the coming into being on earth, but as if in the manner of the aevum, which further reflects the crucial tension and the Trinitarian experience of her spiritual charisma.