The only 4 months (or 5 in a long year) of 5 weeks would be those with at least 29 days starting on Thursday, those with at least 30 days starting on Wednesday, and those with 31 days starting on Tuesday.
有4個月（或在長年有5個月）會有5個星期，但是至少有29天是從星期四開始，30天是從星期三開始，31天從星期二開始。