pay Zakat you need to fulfill two conditions:
Your assets has to reach the "Nisab"
value, i.e. value equal to
3 oz (28 gms) of pure Gold.
Due date is one HIJRI year from the day your assets reach the
Nisab. If you donít remember the exact date, then choose the earliest
date that allows for safety margin, adhere to it. (eg. 1st of
Ramadan). All your calculations should be based on what you will
possess on the due date not what you possess on the payment day.
your local Imam/Scholar for further details)