I doesnt matter actually... Its just in minutes. The hours dont matter. So ill show an example.
Lets say u want kriss Hallo...
And u go on CF in 07:20 am
U buy some crates and start to open them in 07:25 AM
U get a Kriss Hallo in 07:26 AM!!!!
Just confirmed on Kriss Halloween. When I would have more zp i would test it on the other weapons. U can always donate