Is It Really?
On Wink Day, you wink at everyone you see.
Everyone.
If you are physically unable to wink, then a sly smile is an acceptable substitute, but a blink with both eyes is not.
I'm sure you're already wondering what the consequences of all this winking will be. That's the whole point. You want to have fun with this and take it where it leads you, if you're willing to follow.
Could it get you into some trouble? Only if you play your cards wrongly. If you keep it light and fun, everyone will enjoy it.
Of course, once this catches on (which may take a few years) and everyone is winking at everyone else, some of the luster may fade. Until that time, run with it.
Probably not everyone will ever hear about Wink Day, so you should be able to enjoy it for a good, long time.
Merry Christmas.