Investment Plans executed on previous day

When using the Investment Plans to automatically generate transactions, I have a problem with the execution date.
When the execution date is on a weekend (e.g. April 9), PP generates the transaction at the end of the next business day (e.g. April 11). However, Vanguard Investing pulls the date in, to buy the shares/funds at the end of the previous business day instead. (e.g. April 8).
I know that many investment firms execute the transactions the same way as PP does, but given that Vanguard is the largest provider of Mutual Funds, it would be great to have an option for supporting their approach on investment plans.

Hey Duckman,
I do not know if this helps but automatic bookings in PP need to be manually adjusted in the majority of cases as typically at least the rates are not exactly what you bought the shares for. Either you change the date with that or you leave them as for mutual fund investments a day does not play that big a role.
Take care