بسم الله الرحمن الرحيم
(Fatwa: 168/291/D=04/1435)
As per the opinion of Imam Abu Hanifa (رحمة الله) it is 2.5 years, while as per the opinions of Imam Abu Yusuf and Imam Muhammad (رحمهما الله) it is 2 years. The fatwa is based upon the opinion of the later Imams as it is mentioned in Al-Dur Al-Mukhtar the text of Rad al-Muhtar:
حولان و نصف عنده وحولان فقط عندهما وهو الاصح فتح وبه يفتى .
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
