When feeding 10 poor people as an expiation for breaking an oath (kaffarah yameen), does it have to be within the same day?

السلام عليكم ورحمة الله وبركاته ...Or can it be... **a) spread out over 10 consecutive days?** Example: feed 1 poor person today, then another one tomorrow, then 2 the next day...and so on until 10 are fed. **b) spread out over 10 "non-consecutive" days?** Example: feed 1 poor person today, then another one "the day after tomorrow", then 2 the next day, then 1 two days later...and so on until 10 are fed within, let's say, 1 month. Please provide the source for your answer! Jazak Allah khair!