question: public static Calendar reduceCalendarMin ( Calendar calendar ) { int roundedHours = Math . round ( calendar . get ( Calendar . MINUTE ) / 60f ) ; calendar . add ( Calendar . HOUR , roundedHours ) ; calendar . set ( Calendar . MILLISECOND , 0 ) ; calendar . set ( Calendar . SECOND , 0 ) ; calendar . set ( Calendar . MINUTE , 0 ) ; return calendar ; }
target:  sets the supplied calendar object with 0 values for fields lower than hour