In KPK, Winter Holidays will start from 24th December 2018 and will be ended on 31st December 2018.
https://saarinews.com/sri-lanka-govt-announces-scholarships-students-saarc-countries-based.html
Sources that from Last 3 years, Due to Holy Month of Ramadan coming in Summer, Summer Vocation changes slightly lighten.
But Winter Holidays don’t change from last years.
https://saarinews.com/punjab-university-launches-online-admission-system.html