Do you mean can you take all of your holiday in the time you're back at work? You do still acrue holiday as usual while on maternity leave so they can't say you don't get any holiday, but your normal rules would apply to when you can take it. You can't, for example, just say "I am taking 2 weeks off there and there", you would have to request it just like any other person and whether they approve it or not is based on the normal rules. If they have a good reason e.g. somebody else is already off that week, they can say no to you as they would to anybody else. You can put in your request as usual if you want e.g. to cover the whole year if you want to plan ahead, but if you're not going to be there I don't see the point, you'll just be paid for it/take it when you go back if you're on maternity leave anyway, won't you?