New column with datasets coming from API

Hi all,

I’m new in the Power BI and I need to create a dashboard in real time to control different KPIs (visits, amount…) and to do this in this dashboard all the datasets are APIs (Streaming Data) that connect the database (MYSQL) with the power bi. This API return the date in a JSON like this:

 {"TIMESTAMP" :"2017-03-03T08:25:00.000Z", "visits" :"43"}

But to create this dashboard I face different issues:

The first of them is the feature Historic data analysis always need to be enabled in other way the information is not displayed, is that normal?

The second and related with the first is: I send the information nearly each minute but after 2 or 3 days the graphics will be illegible and useless, so the idea is filter to show only the current date, but I don’t find anywhere how to put this filter or if it’s possible.

The third is to sort out the problem with the current date I thought to create a new column inside the power bi to identify the data who belongs the current date and use this new column for the filter but I don’t find anywhere the option to create a new column.

Any help with these problems will be appreciated

Many thanks