Government figures show children in Auckland spent more time in early childhood education than those from any other region last year.
At the same time, the national average number of hours spent in early childhood education has continued to grow.
Children enrolled in early childhood education last year spent an average 19.5 hours a week in education or care. In Auckland, the figure was more than 22 hours.
Radio New Zealand's education correspondent says he national average has steadily increased from nearly 13 hours per week at the start of the decade.
The figures also show about 20% of those aged one and under who were in early childhood education, were there for more than 36 hours per week, as were 22% of all children enrolled in Auckland.
However, Dr Linda Mitchell of the University of Waikato says such long hours could be detrimental if the quality of education and care are poor.