Specify weekend day as workday

Specify weekend day as workday

How can I specify a specific day on a weekend as a work day?  In China, there are many times throughout the year where weekend days are work days to accommodate longer holiday breaks.

Is there some sort of reverse-Holiday calendar that I can set?  Because employees often request time off during that period (a weekend day) and it does not take out from their leave since the system sees it as a weekend (0 work days).