Monday-Friday Happy Hour is from 5pm-8pm.
Saturday-Sunday Happy Hour is from 12pm-8pm:

Heineken Pint - 95 Baht
Tiger Pint - 85 Baht
Standard Bottled Beers - 65 Baht
Standard Coctkails - 99 Baht
House Whiskey - 75 Baht
House Spirits - 80 Baht
House Wine (Red/White) - 80 Baht

Draft Beer Prices Everyday:

Heineken Pint - 150 Baht
Tiger Pint - 130 Baht
Guinness - 220 Baht
Paulaner - 220 Baht
Tetley's Smoothflow - 220

Apart from draft beer The Duke offers a large selection of bottled beers both import and domestic - including Beer Laos. The Duke also has cocktails, fine whiskies, coffees and a selection of wines by the glass and bottle.