PDF distribution of the normalised quenching time for cluster (dark red) and field (blue) galaxies. The quenching time t_quench is divided by the cosmic time τ(z_q) at the redshift z_q at which the galaxy starts quenching. The vertical dotted dark red(blue) line represents the log(t_quench/τ(z_q)) = −1.64(−1.67) separation between fast and slow quenching galaxies in cluster(field).