Chandresh, asterisks in Tableau means "more than one value was returned by the query for this element". I can't look at your workbook right now, but it's likely that whatever you are doing with the data means that Tableau WANTS to show a single date in that spot, but it has multiple dates to choose from, all of which are correct.
Thanks for your reply and thanks for taking time to look at the issue that i am having.
The date column has data from 1st Feb 2018 to 30th April 2018, Tableau is able to only pick dates from 29th March to 30th April and it is converting to " * " for the dates from 1st Feb to 28th March, not sure why
I tried to reformat the dates in excel sheet but no luck...Is there a way creating a calculated field or parameter??