Arrange Cubes

A man has two cubes on his desk.
Every day he arranges both cubes so that the front faces show the current day of the month.
What numbers are on the faces of the cubes to allow this?

Sort the digits on cube 1 and sort the digits on cube 2 and append them to give the answer.

For example, if the first cube had digits 1 2 3 4 5 6 and second had digits 3 1 9 8 2 4,
the sorted digits become :

First cube : 1 2 3 4 5 6
Second cube : 1 2 3 4 8 9

So, the answer would be “123456123489”