Should the wage for the vacation month, the receipt of which was delayed, be included in the money subject to zakat when the annual zakat is paid in Dhul-Qa'dah?

If a year has not passed on the salary you have not yet received, then Zakat (definition) is not obligatory on it until a year has passed. It is permissible to pay Zakat on it in advance, along with the Zakat for the month of Dhu al-Qa'dah. If a year has passed, and you only receive it during your vacation, then you pay Zakat on it when you receive it. It is also permissible to pay its Zakat along with the Zakat of the wealth for Dhu al-Qa'dah.