How do you change date format from YYYY-MM-DD to M

I am loading a flat file to a database table, and need to change the format of the date from YYYY-MM-DD in the flat file, to MM/DD/YYYY in the database table. I tried using the following statement in Derived Columns as shown below, but not sure how to configure the statement, so I got an error message stating that SSIS could not parse the expression.

 
 Derived Column Name:  EFF_DATE 
 Derived Column:       Replace EFF_DATE
 Expression:           TOKEN( MONTH([EFF_DATE]),"//|",DAY([EFF_DATE]),"//|",YEAR([Copy of EFF_DATE]) )
 DATA TYPE:            databasetimestamp[DT_DBTIMESTAMP]

Can anyone help me determine how to change the format of the column in Derived Column? Otherwise, please let me know if there is another way to do it. Thank you.

This question was different from the last one. In the last question, the date column was data type DateTime. But in this question, the date is a string, and when I used the Derived Column to change the date from YYYY-MM-DD to MM/DD/YYYY, it kept the leading zeroes in MM and DD. The issue then became, not just changing the date format, but also removing the leading zeroes from the Month and Day.

However, I researched and came up with a better solution in SSIS for changing the date value with data type string, as the database I am working with stores the date in that format.

I removed the Derived Column from my Data Source Task, and added an Execute SQL Task in the Control Flow, then added the following Update statement which not only changes the format from YYYY-MM-DD to MM/DD/YYYY, but also removes the leading zeroes from Month and Day. The CONCAT function I used the sample SQL below changes the format from YYYY-MM-DD to MM/DD/YYYY, while the Convert function changes the MM and DD values to data type INT which removed any leading Zeros. This solution allowed the date to remain a string, as that was the table format I had to work with.

 
UPDATE [StagingTable] 
SET START_DATE = 
CONCAT( CONVERT(INT, SUBSTRING(START_DATE, 6,2)), '/', CONVERT(INT, RIGHT(START_DATE, 2)),'/', LEFT(START_DATE,4) )]

Thanks to everyone for their comments, as it helped me to think outside the box and determine this solution.