Calculating Nearest Sunday

Hello all,

How to calculate the nearest Sunday?

• 2012/12/30 (Previous Sunday)
  
• 2013/01/03(Today)
  
• 2013/01/06(Coming Sunday)

Here considering today's date(2013/01/03) the nearest Sunday is coming Sunday(2013/01/06)

How to achieve this using AutoIt? any function close to this?

Thanks