Can the Sunnah prayer associated with the second time slot be performed if the first time slot has passed?
Chapter on the Traveler's Prayer
Al-Mughni
Book of Prayer
Primary text
If one performs the obligatory prayer (Fard) within the time slot of the first of two prayers that can be combined (Jama'), one may perform the associated Sunnah prayer for the second time slot before the time of the second obligatory prayer begins. This is because the Sunnah prayer is subsidiary to the Fard prayer it follows, and thus its performance and timing follow the timing of the Fard prayer it accompanies.