Is Zakat obligatory on money saved for two years, which sometimes decreases and sometimes increases, given that the exact start date of the saving is unknown except that it was in the year 1439 AH? And is it obligatory to pay Zakat for the previous two years, and what is the expiation for not paying it? And is it permissible to give Zakat to one's mother? And what should a woman do who vowed to feed 60 needy people upon the arrival of her delayed menstrual period due to polycystic ovary syndrome, and it arrived but she did not feed them?

Zakat (definition) is obligatory on money under two conditions: that it reaches the nisab (definition) (minimum threshold), which is 85 grams of gold or 595 grams of silver, and that a hawl (lunar year) passes over it. The amount of zakat is a quarter of a tenth (2.5%). If the money falls below the nisab during the hawl, there is no zakat on it until it reaches the nisab again and a hawl passes over it. Zakat for the past two years must be paid if it was obligatory and not disbursed. As for the conditional vow to feed sixty poor people, it must be fulfilled as long as the condition it was tied to has occurred.