I would like to set up a recurring transfer that is guaranteed to arrive at its destination by a certain date.
Example
A recurring transfer is delivered from Online Savings Account 123 to Checking Account 456 every other Wednesday. That is, it is deposited into Account 456 on the Wednesday.
What I've tried
I have tried to estimate delivery times by sending the money 3 days before I need it to be in the destination. However, this is not 100% accurate. Furthermore, I have to estimate even more time if a holiday or weekend occurs within the 3 day window. This can lead to human error if I forget to add on the one or two days.
Question
What strategies do people follow when they want to guarantee the arrival time of money transferred between banks? Are my expectations unrealistic? Are there any options to set a "Deliver by" date at certain banks?
More Info
The transfers are initiated online.
Most of the time, I'm transferring funds from an online savings account to a brick and mortar bank.
It is an external transfer (occurs between two different banks).
I am in the United States and all of the banks are also in the United States.