Today is the day I have picked as Tristan's birthday. According to his freeze brand, he was born in 1995. That represents the Bureau of Land Management's best estimate of his age in 1999, when he was rounded up. It would make him 18 this year.
It's impossible to know when he was born, exactly, but there's a decent chance it was spring. My grandmother's birthday was April 11, and she died just a few months before I met Tristan for the first time, so I celebrate it as his birthday.
Some years I have made cake, but not this year. We had a quiet walk around the indoor, and I groomed him thoroughly and hung an Uncle Jimmy's Hanging Balls toy in his stall for him. He didn't seem interested yet but he had hay left, so he was pursuing that.
Here's the birthday boy while handwalking.