I am interested in pouring concrete 'pyramid-like' stairs. I would prefer to do this one stair at a time. How long should I wait for the first stair to cure before I pour another?

Thank You

Wait till the next day

You can lay the concrete in one go as the stairs rest on a uniform slab below on the form work and start using the after 7 days when conc. Get its 2/3rd strength, safely.
Can you let me know the mix (M-20/25 etc) of the conc and the span of the grid?