The progress of a first-order reaction is monitored by spectrophotometry. The reactant is the only colored specie in the reaction mixture with an absorptivity of 6.42×10² M⁻¹•cm⁻¹ at 635 nm. The reaction is carried out in a 1.00 cm quartz sample cell and the initial absorbance is 0.245. At what time will the absorbance fall to 0.165 if the rate constant is 3.48×10⁻² s⁻¹ at 300 K?