University Time table using GA

Looking for a GA based university timetable scheduling script. I have developed one or more varients as below:

1. Chromosome: A-B-C-Z.. where each course as a gene. Now if 'A' is 3 hr in a week, and all allowed combinations are pre-stored in a lookup table. So for a gene value in between 0-->1, descipher a combination (Mon3-Tue7-Fri8, like that). Initial population random, non necessirily conflict free!. Fitness function measures number of conflict.

2. Chromosome: A1-A2-A3-B1-B2-- all course and weekly hours are individual gene. So, each of them takes single slot from 5d*7h = 35 values. Fitness include course, teacher, time conflict. Works, but fitness doesnot go below a certain value, where conflicts are still there.

So, looking for something, where some slots can be prefixed (predefined time slot), faculty hard-constrain can be mapped.

Suggession on logic, or with code is appreciated.