In a cell cycle, the phase of minimum duration is
M phase (Mitosis phase)
It is significant to note that 24 hours is the average duration of the human cell cycle. Out of those 24 hours, the shortest is the phase of Cell division (Mitotic phase) that lasts for only about an hour. The interphase lasts more than 95% of the duration of the cell cycle. Interphase includes G1, S, G2 phases.