The answer depends on which English-speaking country you're in. Both Franck and Dan are right, but for different countries:
- In the United Kingdom, it's a "bank holiday" (meaning the banks are closed). - In the United States, it's a "holiday."
- In many other English-speaking countries (e.g. New Zealand and Australia), it's a "public holiday."
Why do Americans say only "holiday" while many other countries say "public holiday"? Countries such as New Zealand and Australia use "holiday" generally to mean either un jour férié or else the holidays that you choose for yourself. Therefore, if people there want to be more specific and talk only about un jour férié", they say "public holiday." If they say only "holiday", the meaning depends on the context.
In contrast, Americans use "vacation day" to mean a day that you choose to take off work, but not un jour férié. Therefore, when Americans use "holiday", they usually mean only un jour férié.
Confused? Originally from New Zealand, I've lived in the United States for many years now and even though I'm a native English speaker, I still sometimes learn new things about how English is used differently in different countries!