Is it not a hardship to make up the fast of the day on which menstruation began just minutes before the Maghrib call to prayer? And will the fasting person be rewarded for their fast that was not completed due to menstruation?

The nullifiers of fasting are stipulated in the Quran and Sunnah, and they do not differentiate between small and large quantities. Whoever eats a grain of rice or drinks a drop of water has broken their fast, by scholarly consensus. A woman's menstruation nullifies her fast by consensus, and she must make up for it. This hardship is minor and tolerable, and it does not prevent the establishment of religious obligation, as hardships in acts of worship are of two types: The first is that which is inseparable from the worship, such as fasting in hot weather. The second is that which is separable from it, and these are of three types: high, low, and in-between, not all of which negate the obligation.

If a woman menstruates while fasting, her fast is invalidated and she must make up for it. However, it is hoped that Allah will record for her the reward for the portion of the day she fasted, because she fasted by Allah's command and broke her fast due to an excuse from Him, just as it was mentioned regarding the emigrant who dies before reaching his destination, and the pilgrim who dies on the way: "And whoever leaves his home as an emigrant to Allah and His Messenger and then death overtakes him—his reward has already become incumbent upon Allah. And Allah is ever Forgiving and Merciful." [Quran 4:100]. Thus, a woman who experiences menstruation during fasting is rewarded for her fasting and her intention to complete it.