(d)[ Every such person who is appointed to an urban unit shall be liable, for the purpose of firing the annual musketry course, to be embodied for a period of one day in the year in addition to the period prescribed in clause W. he period of one day of embodiment for the purpose of firing annual musketry course may be increased to twodays in cases where the training could not be completed in one day provided that the increased period of one day is within the maximum period of annual training laid down in clause W. Such period of embodiment shall only take place on Sundays or recognised holidays.]