can you please advise if the wall will be open? What hours?

we are looking to visit the great wall on 25th december. we will be travelling from Beijing train station can you advise the best one to travel from on that date and where too. We would like to spend most of the day walking as far as we can however appreciate that due to the weather some places may be more dangerous than others, please could you advise the best place to visit?
Thank you.