Firstly: 

It is not permissible to give zakaah on wealth or zakaat al-fitr to kaafirs, and it is not permissible to give zakaah to any kaafir except the one who is inclined towards Islam, in the sense that you hope that he will become Muslim if you give him zakaah. 

See question no. 39655 and 21384. 

Secondly: 

Once zakaah becomes due on wealth, it must be paid immediately, and it is not permissible to delay it. 

Ibn Qudaamah al-Maqdisi (may Allaah have mercy on him) said: 

If he delays it – i.e., zakaah – in order to give it to one who is more entitled to it among his relatives, or to one who is in great need, if it is a small amount there is nothing wrong with that, but if it is a large amount, it is not permissible. 

Al-Mughni, 2/290 

The scholars of the Standing Committee were asked about an organization which collects zakaah from the rich then delays distributing it for a year, on the grounds that there is help in the springtime, help in Ramadaan and so on. What is the ruling on this delay, since the owners of the wealth have discharged their duty of paying zakaah and have given it to us (to distribute)? 

They replied: 

This organization should distribute the zakaah to those who are entitled to it and not delay it if they have found people who are entitled to it. 

Fataawa al-Lajnah al-Daa’imah li’l-Buhooth al’Ilmiyyah wa’l-Ifta’, 9/402 

See also question no. 13981. 

But on occasion it may be more useful not to give the zakaah to a poor person in one go, so that he will not spend it all and be left with no money; in that case he may be given something each month. 

In this case you should discuss the matter with the rich, and collect zakaah from them a year ahead, then give it to the poor in monthly installments, or take it from the rich ahead of time in installments and give it to the poor in monthly payments. Then it will not be delayed after it has become obligatory. This requires discussing it with the rich and convincing them of the good purposes that will be served by that. 

Ibn Qudaamah al-Maqdisi (may Allaah have mercy on him) said: 

Ahmad said: It is not permissible to give zakaah to his relatives in monthly installments, i.e., he should not delay paying it so that he can give it to them in separate amounts, giving them something each month. But if he pays it all to them ahead of time, or to others in separate payments or all at once, that is permissible because it is not being delayed from its time.  

End quote from al-Mughni, 2/290 

The scholars of the Standing Committee were asked: 

Is it permissible for me to pay my zakaah in advance for the whole year, in the form of regular payments to a poor family each month? 

They replied: 

There is nothing wrong with giving zakaah before one full year has passed, one or two years in advance, if a good purpose will be served by that, and it is given to a deserving poor family on a monthly basis.

Fataawa al-Lajnah al-Daa’imah, 9/422 

With regard to giving zakaah every month in the form of food, please see question no. 45242 .