If this is in your main window you can set a dynamic page break. Here is how to do this.
Say the name of the page in which you want to create the break is 'FIRST' page.
In the main window of this page create a command node in the navigation tree. In the general attributes tab arke the check box 'Go to new page' and in the next field by the check box chose the same page ie 'FIRST'. In the conditions tab of the command window give the condition to check if the month has changed. This will cause the output of the main window to continue on a new page.