Independent think-tank Reform Scotland made the claim in a new report which said some children could receive almost one year less of government-funded nursery education, depending on when their birthday falls.
It has now called for all youngsters to receive two full years of funded nursery provisions.
To achieve this aim, it suggested government-funded provision for all youngsters should begin at a fixed point in the year - probably August – two years before children start at school.
“Every child should be entitled to two years of government-funded nursery provision, regardless of when their birthday falls,” it says
Alison Payne, research director at the think-tank, said: “It cannot be deemed to be fair that children and hard-pressed families are offered divergent periods of funded nursery provision.”