Evaluation version?

[KST75]

I got this message when I first time put in a blu ray movie and used makemkv.

"Using direct disc access mode
Evaluation version, 18 day(s) out of 30 remaining"

Now 18 days lesf. But what does this mean? Can't find anything anywhere about it.

[mike admin]

http://www.makemkv.com/forum2/viewtopic.php?f=5&t=1053