Date Expression help - Next_Day(date,weekday)

Date Expression help - Next_Day(date,weekday)

For any given date, I need to know the next Sunday date -  for example, in Oracle the formula would be:

NEXT_DAY('18-JUN-2014', 'Sunday') would yield June 22 2014

I could create a lookup table with every date, and the corresponding Sunday, but I prefer to create a formula.

Any suggestions?