Triennial readings are already posted on the bottom of each parasha page if they differ in future cycles. Scroll down to the bottom of a parasha page and look for "Triennial readings for previous and future cycles".

In addition, you can also download triennial leyning schedules for 10 years into the future in CSV format here:

https://www.hebcal.com/sedrot/#download

at the bottom of the page you will see something that says 

Triennial readings for previous and future cycles

Thanks for this suggestion. We will look into implementing something similar.

Hello, thanks for using Hebcal. The 11 of Sivan begins Thursday night at sundown, and the majority of 11 Sivan is in fact on Friday.

https://www.hebcal.com/converter/?hd=11&hm=Sivan&hy=5779&h2g=1

Hello, thanks for using Hebcal!

We have added documentation for the lg= parameter to this API:

https://www.hebcal.com/home/195/jewish-calendar-rest-api

Hi, thanks for using Hebcal!

We don't see the error - could you explain which day in May or June is incorrectly shown as ניסן when in fact it's supposed to be סיון

Thanks for the clarification. You can definitely use this API to get exactly what you want. Just specify nx=off&nh=off&s=on 

https://www.hebcal.com/home/195/jewish-calendar-rest-api

We don't appreciate this negative and corrosive language.

Hebcal is free software. Please take your business elsewhere. 

You can get a list of holiday names here:

https://raw.githubusercontent.com/hebcal/dotcom/master/hebcal.com/dist/festival.xml

And you'll find a list of parasha names here:

https://raw.githubusercontent.com/hebcal/dotcom/master/hebcal.com/dist/aliyah.xml

Hi, sorry, the converter API does not support Israel; it only supports Diaspora.

To get parasha haShavua via API for Israel, please use this advanced API instead:

https://www.hebcal.com/home/219/hebrew-date-converter-rest-api