Does Zakat become obligatory on money a man saves or sends to his father, and how is its Zakat calculated if it is due?

Zakat (definition) is obligatory on saved money from salary under two conditions: reaching the nisab (definition) (85 grams of gold or 595 grams of silver), and the passing of a full lunar year (hawl) on the nisab. So, whoever possesses this money and it remains with them for a lunar year, Zakat becomes obligatory on it at a rate of 2.5%, whether they keep it saved or send it to their father, as long as it remains in their possession and does not fall below the nisab. However, if they send it to their father as a gift, or if it falls below the nisab during the year, then Zakat is not obligatory on it.