I erroneously entered the wrong date for the birthday of one of the people listed on my Hebrew calendar. Is there any way i can remove the error and enter the correct date without redoing the entire calendar from the beginning?

Hi, thanks for using Hebcal.

To make a change to a Yahrzeit + Anniversary calendar calendar, delete or unsubscribe from the calendar. Return to Hebcal.com and re-enter in all of the event details, then download again. Hebcal does not yet support editing event dates.

To avoid storing sensitive user data on our servers, Hebcal.com recently modified our Yahrzeit + Anniversary calendar export to “download” instead of “subscribe” calendars. This change affects Yahrzeit + Anniversary calendars created on Hebcal beginning in January 2014, and it applies across iOS, Mac Desktop, Microsoft Outlook, etc.

https://www.hebcal.com/home/632/how-to-make-changes-to-a-yahrzeit-anniversary-calendar