Is it valid when making du'a to specify the time for acceptance? For example, to say: O Allah, do not let this year end except that You have answered my du'a. There is no problem with that.

In this du'a, to say: Answer me now, hasten the response, there is no problem with that, insha'Allah the Exalted.

Is zakat on shares and trade calculated based on their purchase cost or their current value? No, on their current value.

Because suppose the opposite, for example, someone bought goods for a thousand dinars.

And now the goods are worth three thousand dinars.

So they say: He should pay zakat on a thousand. Meaning, he bought them for a thousand, but you make him pay on three thousand, meaning someone paid extra.

We said, okay, the merchandise was bought for a thousand, now it's not even worth a hundred dinars.

Should he pay zakat on a hundred or on a thousand? What does he say?

No, on a hundred, because I lost. The son of Adam is greedy. Allah is the one who helps. He does not pay zakat based on today's reality, on its reality, and there is no injustice in that.

Based on its reality today, whether you have gained or lost, it's based on its reality today.