later on or at a later date?

[bosun]

What is the differnece between later on and at a later date?
Can i say like
The rest of your order will be sent to you later on? If no, why?

[mykwyner]

At a later date is more definite and more formal.

Later on is informal and sounds similar to, "when I get around to it," or, "when I feel like it."