NORGAD, the most common problem with time/date settings is a battery failure - but you have replaced the battery. Are your BIOS settings retained after switch off? The only things I can think of are :
1. Your new battery may be faulty. Can you check it with a voltmeter?
2. You have left the Clear CMOS link in the CLEAR position.
3. There is a fault in the motherboard clock function.