As none of the existing solutions covered my need to fetch public holidays programmatically, I've decided to build my own. holidays.rest distinguishes from others by providing a well-designed API that comes with ready-to-import Postman and Insomnia collections. The API provides full flexibility with tons of different filtering options which you can combine however you like. It's also updated daily and offers a free plan, that will likely be sufficient for personal use and low-traffic environments.