Where insanity does not last the entire year and there is a period of recovery, internal Hanafi opinions differ on how capacity is measured: an attribution to Abu Hanifa gives weight to recovery at the beginning and end of the year; Abu Yusuf considers the greater part of the year; Muhammad gives effect to recovery in part of the year.
The disagreement concerns the amount and placement of legal capacity within the qualifying year, beyond the summary rule about an insane person.