On the Yun Enterprises page, it says:

And if I remember right when I converted Catricia, it was pretty much exactly three days. Now, I want to create (not convert) a pet, and I was thinking of having them have a specific birthday. So I have two questions:

• If you create a steamworks pet, which date is their birthday - the date you requested that they be made, or the date on which they are done?
• If it is the latter, is it always exactly three days after you make the request?

I wanted to make sure I get the timing right.

It's the date you start the process on

I no longer own the pet, but I had one once where I was sort of going for a relevant date but it wasn't super important if I got it or not. The finish date would've been the date in question but their birthday/build day is three days early

Ah okay - so it's the date you start the process on. That is a lot easier to plan for. Now I just have to decide if I want to wait for that date and risk the name I want being taken in the meantime. :)

Thanks !