In the name of Allah, the most Beneficent, the most Merciful.
Zakat is compulsory upon a person who possesses the quantum of nisab (i.e. 612.35 grams of silver or 87.47 grams of gold or currency, wealth equivalent to that amount) for a complete lunar year; which is over and above his basic needs and also free from debts. (Raddul Muhtar Vol 2, P5)
If an individual has in his possession wealth, which is free from his basic needs, and this amount after deduction of liabilities exceeds the quantum of nisaab then it will be compulsory to pay zakat (2.5%) upon passing of a complete lunar year.
With regards to your question there are two situations:
1. If you only have the maintenance grant and no other saving then as you did not have it in your possession for a year, Zakat would not be obligatory for this lunar year.
2. If you had other savings besides the maintenance grant then the maintenance grant would have to be added with the other savings and Zakat given on that amont. It is mentioned in Aapke Masail that if a person became a Sahib Nisaab, then the year following that (i.e. on the same date when he became Sahib Nisaab) he has to give zakat on all his wealth that he has with him at that time, regardless, of when he acquired wealth during the course of the year. It may happen that some of the wealth he is giving zakat on, did not remain with him for a full year. (Aapke Masail p.356 v.3)
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham