by Robin Nayler
My five grandchildren were all born before noon in different years and in different months.
For each of them I have noted their time and date of birth in the order minute, hour, day, month and year. None of these numbers is zero but the latter three each have two digits with a possible leading zero.
For each grandchild, the five numbers form an increasing or decreasing arithmetic progression in which the sum of two of the numbers is equal to the sum of the other three.
From oldest to youngest, list the months in which they were born.