Is zakat obligatory on money saved for Hajj, marriage, and purchasing land, and how is it to be rendered?

Zakat is obligatory if the wealth reaches the nisab (threshold), which is approximately 85 grams of gold or 595 grams of silver, and a full lunar year (hawl) passes without the wealth decreasing below this amount. The amount due is one-quarter of one-tenth (2.5%). However, if the wealth does not reach the nisab or is spent before the hawl, then no zakat is due on it. If zakat becomes obligatory but is not paid, the giver must pay it for all past years, as it is a debt upon them. As for land, if it was purchased with the intention of trade, its value is assessed, and your share of it is subject to zakat if it reaches the nisab. If it was not purchased with the intention of trade, then no zakat is due on it.