Dates are not like other types of data. They are not exactly a number and not exactly a name. Dates also have a built-in hierarhical structure. For example, a single day can be broken down into hours and minutes. And days are a part of months and years. In this article, you will learn about, how tableau treats date fields to handle these differences, and more. For relational data sources, Tableau automatically detects dates and places them in the dimensions area of the data pane. You can tell a field is a date field because of the icon next to it. If the data includes a time of day, Tableau will automatically make it a Date-time field. When you bring a date field into a view, Tableau will automatically uses the largest part of the date hierarchy in your data. Often this is Year. But you don’t have to stick with the default. Change it to Month,Day-whatever level of granularity that you want. For instance, we will stick with year. Date fields can be used as either date parts or date values. Date parts are individual components of the date, such as Month or Day. For example if we use a month date part in a view, Tableau will ignore other components. Date values are complete, specific dates to a specific level of detail. A date value could have a year, month and day, or also could even include hours, and seconds. If we use a month date value in th view, Tableau will aggregate all our data. Into the month and year in which it belongs, ignoring lower date parts in the hierarchy. Such as Day and Time. For example, january 2014, january 2015, and january 2016 etc.
In this article we have talked about Date Parts And Date Values. Remember most data analysis are include date fields.So date fields are important. We will talk about Discrete and Continuous fields in next article.