Potassium chlorate is prepared by the electrolysis of KCl in basic solution 6OH−+Cl−→ClO3−+3H2O+6e−.  If only 60% of the current is utilized in the reaction, the time (rounded to the nearest hour) required to produce 10g of KClO3 using a current of 2 A is______(Given : F=96,500 C mol−1; molar mass of KClO3=122    g   mol−1)