Used for rendering the cell content of the Calendar. To define the cell template, nest an <ng-template> tag
with the kendoCalendarCellTemplate directive inside the component tag. The template context is set to the
current component. To get a reference to the current date, use the let-date directive. To provide more details
about the current cell, get a reference to the current cellContext by using the let-cellContext directive.

For more examples, refer to the article on templates.

kendoCalendarCellTemplate is equivalent to

selector: 'my-app',
styles: ['.custom { color: red; }'],
template: `
   <ng-template kendoCalendarCellTemplate let-date>
     <span class="custom">{{date.getDate()}}</span>
class AppComponent { }