Dark Horse: They use a bottling date which is located halfway up the neck of the bottle in Julian format: DDD-YY. First three numbers are the day of the year. YY is the last 2 digits of the year. 13=2013.

DC Brau: They use a canned on date which is a sticker on the top of each six-pack, format is MMDDYY. No dates on the bombers though.

Deschutes: They display a best before date as month (but not year). Listed as month/day/year and is 120 days out. Black Butte & Obsidian is 200 days. They also use a best after date on their Reserve Series.

Detroit Beer Co: They use a bottled on date which is printed on the glass below the label, usually towards the back label. Format is a random letter or two followed by the date of the month, the month spelled out and the year. Ex: S21NOV2013.

Devils Backbone: They use a bottled on date.

Diamond Knot: They use a bottling date.

Dick's: They use a brewed on date which is stamped on the outside of their cases.

Dillon Dam: They use a bottled on date which is on the case package and the shelf-life is 90 days.

D.L. Geary's: They use a bottling date which is located on the top of the end panel of the case boxes. Format is MM/DD/YY.

Dogfish Head: Shows the date bottling on the neck of the bottle. DD/MM/ YY format.

Drake's: They use a bottling date, it's in the format of MM/DD/YY in yellow ink on all bottles between the neck and the shoulder of the bottle. The cases are stamped with the date before they are palletized. 

Duck Rabbit: They use an enjoy by date. Month and year are notched on the right side of the front label.

DuClaw: They use bottling date.

Durango: They use a bottling date which is stamped on the case.

Dunedin: They use a batch code which is located on the neck of the bottle in black ink. You have to email the code to the brewery to find out the date.

Duquesne Beer: They use a brewed date on all of their cases.

Dust Bowl: They use a bottled on date which is located on the bottom left of the front label.