Kendo Angular dynamic grid custom object format

Has anyone got any idea on how to format the display for a custom object in a Kendo Grid?
I have the following dynamic grid:

<kendo-grid
    <kendo-grid-column
      *ngFor="let column of columns"
      [field]="column.field"
      [title]="column.title"
      [format]="column.format"
      [filter]="column.filter"
    ></kendo-grid-column>
</kendo-grid>

and I have a column that stores a simple day / month object:

dayMonth: {
    day: number,
    month: number
}

and I already have a dayMonthFormatter pipe to display this in a "dd MMMM" format. What I can’t figure out is, without having to change the data returned by my API, how I can get the Kendo grid to apply the pipe to the data by using the [format] input. The ColumnComponent documentation refers to supporting an ‘format object’, but I can’t find any reference anywhere on how to create a custom one of these.

Source: Angular Questions