question: public static int mDateGap ( String dayName ) { Log . d ( "dayname" , dayName ) ; if ( dayName . equals ( "mon" ) ) { return 1 ; } else if ( dayName . equals ( "tue" ) ) { return 2 ; } else if ( dayName . equals ( "wed" ) ) { return 3 ; } else if ( dayName . equals ( "thu" ) ) { return 4 ; } else if ( dayName . equals ( "fri" ) ) { return 5 ; } else if ( dayName . equals ( "sat" ) ) { return 6 ; } else { return 0 ; } }
target:  Get the day difference in the selected day and the first day in the week 