add month to date in apex code example

Example: add month to date in apex

date + ( ( 365 / 12 ) * Number_months )
  
//or
  
DATE(
  YEAR( date ) + FLOOR( ( MONTH ( date ) + 2 - 1 ) / 12 ),
  MOD( MONTH ( date ) + 2 - 1 + 
    IF( DAY ( date ) > CASE( MOD( MONTH( date ) + 2 - 1, 12 ) + 1, 
      2, 28,
      4, 30,
      6, 30,
      9, 30, 
      11, 30,
      31 ), 1, 0 ), 12 ) + 1,
    IF( DAY( date ) > CASE( MOD( MONTH( date ) + 2 - 1, 12 ) + 1,
      2, 28, 
      4, 30, 
      6, 30, 
      9, 30, 
      11, 30, 
      31 ), 
    1, DAY( date )
  )
)