creditors calling on weekends

Have you already filed for bankruptcy? If so, there should be an automatic stay in which the creditors can have no contact with you. You need to contact your bankruptcy attorney and let him know so he can handle the situation.

The creditors are restricted to do certain number of calls in a week or in a month. I don't think they are disallowed to do it on Sundays. They can make the calls and if they are doing it repeatedly, you can express your concerns not to do it in frequent intervals.

Only third party collectors have to abide by the FDPCA. Original debtors can call all they want, at any time.
But Tammy is right, the only way you'll keep them from calling right now is to talk with your bankruptcy attorney, they can not call if you filed already.