Impact of GOLIVE date change

Hi,

What is the impact of GOLIVE date change

Example:-

1. If suppose golive date is 31st, December, If it will extent to Jan 15th, what is the impact.

2. If suppose golive date is Oct1st, If it change to 1st December, what is the impact.

Can you please clarify anybody.Apprreciates early comments.

Regards

Srinivas