V-calendar add multiple selector and also highlight dates in attributes

I am using v-calendar for the first time and I am kinda stucked. I want to highlight some specific days and days that I selected. e.g. from this website where I can select all the dates and save into a list.
See this example: Date Pickers | V-Calendar

<v-calendar :attributes="attributes" @dayclick="onDayClick" />
 computed: {
    dates() {
      return this.days.map(day => day.date);
    attributes() {
      return this.dates.map(date => ({
        highlight: true,
        dates: date,

and when I want at the same time also highlight something with the attributes, it wont work since attributes is used above in computed.

e.g. Attributes | V-Calendar

  data() {
    return {
      attributes: [
          key: 'today',
          highlight: true,
          dates: new Date(),

So my question is, how do I combine the multiple dates selector with another attributes?