I have the date as YYYY-MM-DD in kibana, I want to convert this one to date, so that i can use it in Visualisation.
You can use runtime fields to do your mapping. or scripted fields if you are on a version older than 7.11 of elasticstack.
You can do it using UI in kibana -
Where can i see the output of runtime fields , i am not able to see it, if i create scripted fields and i use it in kibana, i am getting aggregation errors.