Hi, similar age here.
First became "seriously" suicidal (after spending most of my life thinking about it daily without intent) in 2021 when we'd both have been 26.
When I was 27 I thought I'd like to die before I turned 28 - pretty stupid given I'm not a musician and don't have any creative achievements at all. Had either June or September in mind - I'd rather die after a warm sunny day than after a cold rainy day, and I have lots of friends and family with birthdays in July and August I don't want to ruin.
When I was 28 I thought I'd kill myself in September for sure, but ended up hospitalised instead.
This year I had a friend's wedding in June to keep me on track then. At times I did think I couldn't bare to keep going and would just kill myself quickly to end things, but I obviously haven't. Right now I am still considering dying in September.
I have a holiday booked for my 30th birthday and I guess staying alive to go on that gives me something to keep going for, though I don't know if I'll make it. After that, I think if I still want to kill myself I'll blow through my life savings on a long holiday and then kill myself late next year, probably October?