I am not quite sure what you are asking.

I downloaded  used the Hecal app, filled in the information required and did not enter (include) a name on the first calendar which I inadvertently did not under after sundown. 

I later created another calendar calendar, this one "after sunset" and named it Lin. Everything was created using W10 and I used the same email address for BOTH calendars 

Thank you for your prompt reply, can you please advise me how do I find/identify the calendars that I have (that I created) so that I can delete them and start over?

Bob