All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The basic principle is that whoever owes Zakat on his wealth must pay it immediately, and it is not permissible for him to delay it with the ability to do so because it is the right of those whom Allah has imposed it for.
You did not tell us why you could not pay your Zakat on time, but if you could not pay it out when a whole lunar year has passed, you may delay it until the time when you will be able to pay it out.
An-Nawawi said in Sharh al-Muhadhab:
“Zakat in our view must be paid immediately. When it becomes due and the person is able to pay it out, then it is not permissible to delay it. If he is unable to pay it out, he may delay it until he can afford it. If he delays it after being able to pay it out, he is disobedient and becomes a guarantor.” [End of quote]
For more benefit on Zakat, please refer to Fatawa 165375, 401332 and 379973.
Allah knows best.