What is the amount of zakat due on a sum of 27,187, knowing that it is in a bank account opened on 2/10/2011?

Zakat is obligatory on money under two conditions: reaching the nisab (the equivalent of 85 grams of gold or 595 grams of silver), and the passing of a complete hawl (one lunar year) while owning it. If both conditions are met, 2.5% of the amount is to be given. If the amount is less than the nisab or a complete hawl has not passed, then there is no zakat on it. If the amount was accumulated in installments, then what matters is the day it reached the nisab.