What expiration information is available on the carton of yogurt?

Yogurt products are imprinted with a "sell by" date, a 'best before" date or a "best if consumed by" date that include the month, day, and year. That date (if it's a "sell-by" or "best before" date) is approximately one month from the date the yogurt is put on the shelf.     
 
Source(s):  
Dannon recorded consumer help line:  1-877-DANNONUS
Interview with Dannon consumer relations representative. 
Stonyfield Farms recorded consumer help line:   1-800-PRO-COWS (776-2697)
Interview with Stonyfield Farms consumer relations representative.
Stonyfield Farms “Frequently Asked Questions”