Thanks, got it! I've implemented some logic into my code that now fetches time from the internet and then compares it to the JSON item dates from Hebcal, if the date is not in the future, it moves on to the next item. 

What is actually the difference between the Jewish calendar API and the Shabbat API? Both seem to return Jewish Holidays, Candle Lighting times and Havdalah times. Or is it just the more parameter control options?

Thanks a lot!! I see what you mean indeed.

Since I am programming this application on a microcontroller I find it difficult to extract certain JSON data and make HTTP requests, I'm using C/C++. If it were for Python I think I would have been able to implement that logic, to skip the previous dates in the JSON data and only use the ones for the future.

However, since I plan to only send a request once a day (now for testing maybe a little more), I hope to not put that much load on the servers and use the cache-control: no-cache as my solution for now :). 

Thanks once again.

Hi Michael, thanks for your reply! That makes sense.

"The longer answer is that our server config isn't respecting Cache-control: no-cache and we should fix that."

I hope I'm not rude asking, since this is a great API and possibly maintainted in your free time, but will it really be fixed too? Or only maybe later on in development? :)

Thanks for any help once again.