I think now would be ok as long as the earth isn`t frozen. I hope you have male and femail Skimmia`s as they like to fertilise if you want flowers to berry later in the year.
Alan Titchmarsh says March. It was in the Mail on Sunday last week and the week before. Also I have been gardening for years, and I move shrubs around in March without any problems.When you move them you need to keep the root ball as intact as possible and make sure you do not let them dry out for a good few months after transplanting them.
PS Dont forget to talk to them whilst you are moving them. Apologise for disturbing them. It works for me! lol