How Does Dateadd Impact the Performance of a SQL Query?

Question

Say for instance I'm joining on a number table to perform some operation between two dates in a subquery, like so:

select n
      ,(select avg(col1)
          from table1
         where timestamp between dateadd(minute, 15*n, @ArbitraryDate) 
                             and dateadd(minute, 15*(n+1), @ArbitraryDate))
  from numbers
 where n < 1200

Would the query perform better if I, say, constructed the date from concatenating varchars than using the dateadd function?

Answer 1

Keeping data in the datetime format using DATEADD is most likely to be quicker

Check this question: Most efficient way in SQL Server to get date from date+time?

The accepted answer (not me!) demonstrates DATEADD over string conversions. I've seen another too many years ago that showed the same