Change default boot item depending on daytime

[Roland Berger]

Hi

There is a 3 year old thread about this topic and I wonder if there are 
any news about this.
http://lists.gnu.org/archive/html/help-grub/2008-04/msg00029.html

I also have dual boot. During day time I want to automaticaly boot OS1 
during night time I want to automaticaly boot OS2.

With grub2 we have scripting support and I also found a reserved keyword 
"time" but no explenation for it. Can someone give me some information 
about this "time" keyword or even better a solution for my "problem"?

Thanks Roland