In the field GFInsFreqOpt add either of the following values:
  • Specific Day  
  • User Defined day  

Using the screenshot below, 'Specific Day' refers to selecting the first option under Frequency. 'User Defined day' selects the second option.

Payment Installment Schedule record

For more information, refer to How to import pledges and recurring gifts with installment schedules (includes sample data file).