Honesty Day, also known as National Honesyt Day, is celebrated on April 30, 2017. The day was created in the early 1990s by M. Hirsh Goldberg, former press secretary to a governor of Maryland and author. Goldberg did a four year research for his book "The Book of Lies" before, and invented Honesty Day in the month, which begins with a day of lying: April Fools Day. He thought the month should end more honest, than it starts, and also, April 30 is the anniversary of the First inauguration of George Washington in 1789.
According to Goldbergs' "The Book of Lie", the average person lies about 200 times a day. Honesty Day aims to encourage straightforward communication and of course honesty. To celebrate the day, you could for example ask questions you always wanted to get answered honestly. Of course, another way to celebrate the day is to simply be honest. Although Honesty Day sometimes also is refrerred to as National Honesty Day, there seem to be no congressional records or presidential proclamations for this day.