Seeking Both An Age From Birthdate And Nearest Birthdate Qry

I'm having a problem finding the nearest age. If the last bday is closer then the current age, if the next bday is closer then current age + 1 year. I'm familar with dateadd, datediff and datepart. Here's some psudo code...

declare @bday datetime ,@age int
set @bday = '01/26/1956'
set @thisdate = getdate()
set @age = case
when next @bday is closer than the past birthdate then age(@bday) + 1yr
when next @bday is farther than past @bday then age(@bday)
end

I know there is not an age() function, but that's part of what I'm looking for. I'm also stumped on getting the nearest age. What I had only worked for part of the year, prior to around June 15th, (183 days into the year)

TIA

JeffP...