February 7th, 2019 is...
Pisco Sour Day!
Some links of possible interest:
Celebrate The Peruvian Cocktail On World Pisco Sour Day, Feb 7 at ForbesLife
How to make a Pisco Sour at Liquor.com
Wikipedia: Pisco Sour
Drink Days
A semi-comprehensive list of alcohol-themed commemorative days.