DEPOSIT_START_DATE is an optional date field used for only U.S. installations to display the pay period start date where the deposit is to commence after the pre-note period is over.
The pre-notification deposit process completes this field automatically. The deposit start date is the pre-note date plus the number of pre-note days on the bank account (IPBA). The resulting date is used to looks up the pay period calendar to see which pay period the date falls in, it takes the pay issue date from that pay period and then uses it for the deposit start date.
The next UPCALC, when the pay issue date is equal to or greater than the deposit start date - the employee will receive a deposit into this account.