Word that means earliness and lateness at the same time

Solution 1:

I suggest unpunctual.

Unpunctual (adj): Not happening or doing something at the agreed or proper time.

Example: The trains into Tbilisi were notoriously unpunctual. [Lexico]

In your example:

I was expecting my package tomorrow and it arrived today. The package was unpunctual.

(Unforeseen in some similar contexts could also be used.)