@mrjj
I have moved forward from calling my saved dates to receive the following:

Read Value: [object Object],[object Object],[object Object],[object Object],[object Object],[object Object] for key: dates

(one for each date saved)
when adding

if(success) { console.log(JSON.stringify(value)) }

I can also read the saved dates in the format of:

[{"date":"2018-10-01T21:17:00.926"},{"date":"2018-10-02T12:00:00.000"},{"date":"2018-10-03T12:00:00.000"},{"date":"2018-10-06T12:00:00.000"},{"date":"2018-10-07T12:00:00.000"},{"date":"2018-10-08T12:00:00.000"}]

now how would I determine these dates are saved in my calendar to add the marker?

I have tried adding a property bool to the marker so the read value equals isMarked = true yet this either marks every date on the calendar or none at all depending on how I am working this?!?

How would I convert the JSON string to individual date reads?

What exact error did you get ?

What format is it ? How are you retrieving it ?