Odear' ok you can prune laylandii at any time, they tend to grow up and out, to get growth at the bottom you must cut the top off,and keep it to the height you want, if you are useing it as an hedge keep it trimmed, the reason I said Odear is because to most gardners it is a no no, not only is there a law now in britten limeting the height, the roots are the main problem' they will take every drop of moisture in the garden,to the determent of everything else, as they are shallow rooted, they will in time show above ground, my advice would be ,if it is a lone tree , decorate it for christmas' and cut it down in the new year, if it is a hedge treat it as such, and make plans to change for something else, hope this is a help.

I would be very careful with doing any trimming or cutting back in your country at this time of year, I would leave it till the spring.