The list contains three time-sensitive cases:
• sunrise during Fajr;
• zenith during the Eid prayer;
• entry of Asr time during Jumu'ah.
These prayers depend on their own legally defined time windows. The course therefore treats these as named source cases rather than inventing a general rule that “every prayer becomes invalid whenever the next prayer time begins.” For example, Zuhr does not become invalid merely because Asr time enters.