Aditya
It may depend, if you have the luxury of only initiating the campaign once then I would set it so that the campaign starts on the day / date in question, then each and every following email is sent following a wait step of the defined duration (days, weeks, months etc). If you have people coming into the campaign at any point then I suspect a different approach would be needed, and using something like the Date Calculator Cloud Connector looks like it will do the trick. Here's the Topliner link: http://topliners.eloqua.com/mobile/mobile-access.jspa#jive-content?content=%2Fapi%2Fcore%2Fv3%2Fcontents%2F14435
Let us know if that works, there's quite few comments and use cases referencing it. And of course, if this answers your question, marketing this is the correct answer would be great and help all other community users.
Greg