Add a month to a date

[Chris_Stewart]

I've created an meeting space that allows people record their agendas/minutes and I'm trying to add a feature allows them to select reoccurring meetings; weekly, bi-weekly, or monthly. When the user clicks submit, confiforms creates the initial record and additional records with dates every week, bi-weekly or monthly as selected.

I can can create the weekly and bi-weekly records using date=[entry.date.timestamp.add(604800000)] in the IFTTT. I just double the milliseconds for week2 etc. (I'm open to better ways as well)  

Unfortunately, this method does not work for a month because the number of days(milliseconds) fluctuates from month to month.

Does anyone have any ideas on how to add a month to a given date( from field type: Date)?