—This paper presents various semantic interpretations for logics of knowledge and time with prefect recall. We allow both past and future operators and examine the interpretation of different linear flows of time. In particular, we present temporal epistemic logics for each of the following flows of time: arbitrary linear orders; the integers; the rationals; the reals; and for uniform flows of time. (By uniform flows of time, we mean that time is an arbitrary linear order that is common knowledge to all agents). We propose axiomatizations for all logics except the last case, for which we show that no finite axiomatization can be found. The axiomatizations are shown to be sound and complete in the case of arbitrary linear orders and the rationals.