private BigDecimal getLongitudeHour ( Calendar date , Boolean isSunrise ) { int offset = 18 ; if ( isSunrise ) { offset = 6 ; } BigDecimal dividend = BigDecimal . valueOf ( offset ) . subtract ( getBaseLongitudeHour ( ) ) ; BigDecimal addend = divideBy ( dividend , BigDecimal . valueOf ( 24 ) ) ; BigDecimal longHour = getDayOfYear ( date ) . add ( addend ) ; return setScale ( longHour ) ; }
Computes the longitude time t in the algorithm .