Hi, thanks for contacting Hebcal.

The @hebcal/hdate JavaScript source code that you are referencing is licensed under the GPL-2.0 license

https://github.com/hebcal/hdate-js?tab=GPL-2.0-1-ov-file#readme

If you are reusing source code to build your functionality, please be sure to note the The GNU General Public License 2.0 requirements. 

The CC BY 4.0 license applies to content generated by web APIs, but not for source code reuse.

Thank you for using Hebcal! To create a personal list of Yahrzeit (memorial) and Yizkor dates for 20+ years, please visit https://www.hebcal.com/yahrzeit

Thank you for using Hebcal! To create a personal list of Yahrzeit (memorial) and Yizkor dates for 20+ years, please visit https://www.hebcal.com/yahrzeit

Thank you for contacting us and for using the  Hebcal Yahrzeit + Anniversary calendar.

We don't have any calendar of famous rabbi yahrzeits posted on Hebcal.com 

If you find such a list, you can use the Comma Separated Values (CSV) file import feature to upload it to Hebcal. Read more at

https://www.hebcal.com/home/4322/csv-import-for-yahrzeit-anniversary-calendar

Thanks for using Hebcal. In short, no, you should not look to Hebcal to give precise calculations for dates before 1752 CE. Hebcal uses the proleptic Gregorian calendar and does not attempt to compensate for dates that differ prior to the Gregorian reformation.

https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar#:~:text=The%20proleptic%20Gregorian%20calendar%20is,its%20official%20introduction%20in%201582.

Hi, thank you for contacting Hebcal.

The easiest way to do this might be to use Microsoft Excel to create a spreadsheet and use this Excel macro to convert from Gregorian dates to Hebrew dates.

https://www.dafaweek.com/HebCal/HebCalVb6.php

Thank you for using the Hebcal developer APIs. We apologize for the missing CORS header on our Yahrzeit + Anniversary web API. This was indeed a misconfiguration on our end.

This error is now fixed on our end. You should be able to access this API and your browser will receive the correct 

Access-Control-Allow-Origin header.

Hi, thanks for using Hebcal.

You are welcome to use the free Yahrzeit + Anniversary calendar located at https://www.hebcal.com/yahrzeit

This webiste was designed for individuals, not minyanim, so it's quite limited in its features and offers only a few options for customization. We definitely don't have all of the the features you described. For example, there is no login protection - only an "unlisted link" mechanism that permits anyone who has the link to edit the page. At this time, we don't have plans to add additional features like logins, nor do we have any capability to offer any further customization of the current product.

Feel free to use our existing tool as it is, or consider a commercial solution like ShulCloud for your minyan.

Shana Tova and G'mar Chatima Tova! 

Thanks for using Hebcal.

We regret that we currently don't have the expertise to research this. Do you have a good reference you can point to that lists all of the Chabad holidays that are separate from the standard Jewish holidays?

Thank you for using Hebcal. We are sorry to hear you are having difficulty seeing fast days in your Outlook calendar.

Which fast day is missing? We see Tzom Gedaliah on October 6, Asara BTevet on January 10, etc.