Maybe something like this: vuetify-play

  <template>
  <v-app>
    <v-container>
      <v-date-picker></v-date-picker>
    </v-container>
  </v-app>
</template>

<style>
  .v-date-picker-years .v-btn__content::after {
    content: ' Test';
  }
</style>