What's the term for siblings born 1+ years apart on the same day?

What is the term for two siblings born on the same calendar day, one or more years apart? I know there's a term, and I'd know it if I saw it, but I can't for the life of me remember it.

Solution 1:

Aside from saying that you "share a birthday", I am not sure that such a term exists. If it does it isn't likely to be very well known. Restricting it to only match siblings is likely to make things less likely to match up perfectly.

Generally, special birthdays are given a modifier. Most of these are just off the cuff:

• holiday birthday
• shared birthday
• golden birthday
• half-birthday

Other words that could work apart from "shared":

• joint birthday
• combined birthday

You could also go the other way with it and accentuate the negative:

• split birthday

Solution 2:

Are you thinking of "Irish twins"? It's not exactly what you were asking about, but it is the only relevant term I can think of that you might be referring to.

Irish twins are siblings who are close enough in age to be mistaken for twins. I would guess that the expression stems from a perception that Catholics have children in close succession.

https://www.verywell.com/irish-twins-meaning-2447174

Solution 3:

I might call them "yearlings", being a little cheeky.

Although the common usage is a foal between one and two years old, apparently there is a legit usage relating to a one year span:

Yearling (adjective): of a year's duration or standing
_{SOURCE: Dictionary.com}