Ok, thanks. Will try with AppSheet customer service. The ideal solution would be to have an actual Jewish calendar, not as events on a Gregorian calendar.

I can't see any categories on the Google Calendar data. I don't think it's possible to have multiple calendars on one dataset in AppSheet. It will need to be on a separate calendar view, as far as I understand.

Thanks! Looks good. I wonder if there's a way to add a column to the data source (it's not a physical table in AppSheet, as the data is coming in from Google Calendar, so can't add my own column), to add a category for each event. Best would be if every month can have its own category (the month name can be the category) and then Yomim Toivim one category and taaneisim should have a different category, so when it's displayed on the calendar you can clearly see what kind of event it is. This will help in visualising the calendar by month, holiday etc, all having their own colour.

Originally, I created a table in sheets, with column A being the Gregorian Date, and the rest of the columns having the corresponding Jewish dates by day, month, year. The column that has the month is being used as the category. So for example Shvat is a category, so all events (Jewish dates) from Shvat are coloured orange, and every month has its own colour.

Please let me know if it's possible to add categories to events. 

Thanks a lot!

And this is the Google Calendar connected calendar, from Hebcal: