You should know that you have the choice to close your position when you want and nobody can Interference in your decision , you can let your positions open for a week or a month or even a year , you are the only person who decide that but you should know why you let your positions open in the market and don't trade randomly. There is no limitation about how long you open it. Broker have no problem with it. You can use it when necessary. Even I also do it for many times and I never face any problem. So in my opinion there is no any problem if you do this. You also never charged for it.