705th Anniversary of the Declaration of Arbroath!
I’ve never heard of Tartan Day. But we better keep it on the downlow, or the Irish will steal it and reappropriate it, like the did with kilts and pipe bands, the thieving bastards. 
Alba gu bràth!
As a proud alum of Carnegie Mellon, and an editor of The Tartan newspaper, I say, wear it!
I do have a nice dress shirt with the family tartan. Not going anywhere to wear it today.
No Scottish heritage, but am a piper. My band wears the Erskine Modern tartan, which was worn by the pipers of the Royal Scots Fusiliers and is still worn today by the Pipes and Drums of their successor unit the Royal Highland Fusiliers, 2nd Battalion, Royal Regiment of Scotland (2 SCOTS). This tartan was chosen due to association with a WWII reenactment unit doing the RSF. This kilt is my property.
In Canada, I played with the now defunct Richmond Hill Centennial Pipe Band. They wore the Cameron of Erracht tartan (one of my favorite tartans, “erracht” just happens to be my handle on a number of other forums). A kilt I had issued by them was the best fit I ever wore. That band chose that tartan because when it was founded, kilts bearing it were available from military surplus.
This is mine. Comes with batteries 
Hey, it’s National Beer Day!
Though nothing says the two holidays can’t be celebrated together.
Hell, it should be required.
Here’s my tartan- clan Fraser.
Je suis prest!
Here’s mine - Robertson, Clan Donnachaidh of Atholl. Although the notion of clans having unique, personal tartans is a 19th c. Romantic invention. When I was Googling to find an image of the tartan, one of the related questions was “Who can wear the Robertson tartan?” The correct answer: “Anyone who damn well pleases.”
My father’s ancestors were mostly English, but my mother’s ancestors were the proud wearers of the ugliest tartan in all of Scotland.
Buchanan
I do like the look of the family tartan.