Ron is always concerned about his lucky numbers. Even while looking at dates on a calendar or selecting a time to do a particular activity, he is always preoccupied with lucky and unlucky numbers. His symptoms suggest that he might be suffering from a(n)

Obsessive-compulsive disorder

Explanation:

Ron's symptoms suggested that he might be suffering from an obsessive-compulsive disorder which is a mental health disorder that affects people when individuals get engaged in the act of obsessions and compulsions which make them feel driven to do something repetitively and habitual that become so consuming they interfere with the affected individual and cause irreparable damage to their daily activities. This type of mental illness made up of two parts: obsessions and compulsions.

From Ron's scenario, we can deduct that he has an obsession with numbers, to the point of having preference over certain digits which he considered lucky and unlucky numbers, and this obsession leads to his behavioral compulsion on the fixation that affects and preoccupied this mind always.

in about winter like late november to january