Block 10 is based on the estimated settlement date and interest charges from that date through the first of the month, which may be collected as a prepaid at closing.
Line 1 is the lock expiration date, this may or may not be the same as the settlement date.
1. Not Locked: Enter the same date as the date of the GFE. If the loan is locked, enter the lock expiration date
1. Secondary market transactions: Input the lock expiration date (generally locks have 7, 30, 45 or 60 days expiration dates).
2. Banks that do not sell loans in the secondary market and do not have a lock expiration date, can use the estimated settlement date.
Whatever date you input in Line 1, you are bound for all origination charges in Block 1 (and other interest rate dependet charges).