Neds Sheds purchases building materials from TimbertownLumber for $3700 with ter

Neds Sheds purchases building materials from TimbertownLumber for $3700 with terms of 4/15 n/30. The invoice is datedOctober 17. Neds decides to send in a $2000 partial payment. Bywhat date must the partial payment be sent to take advantage of thecash discount?