For cognitive linguist George Lakoff and his colleagues, most poetic metaphors are based on conventional metaphors. But this proposition has yet to be tested by a systematic survey of poetic texts. The present article aims to explore whether data from English poetry are consistent with the idea that most poetic metaphors for time are grounded in conventional ones. From the data for this study, ten schematic elements of time metaphors are extrapolated. The conventionality and novelty of these ten metaphorical elements are then discussed in their respective poetic contexts. The results show that the distinction between poetic and conventional metaphors for time is frequently blurred in English poetry and that, although most of the poems for the present study contain a time metaphor that has a feature of a conventional metaphor, that feature usually is not predominant enough to serve as the fundamental principle of the poetic metaphorization.