Typeerror: undefined is not an object (evaluating '_this.setState')

[glitchwizard]

I'm getting the following error:

with the following component:

import React, { useState } from 'react';
import Background from './components/background';
import { StyleSheet, View, Text, StatusBar } from 'react-native';
import Icon from 'react-native-vector-icons/MaterialCommunityIcons';
import WeekdayPicker from "react-native-weekday-picker";

<link href="https://fonts.googleapis.com/css2?family=Lato:wght@300&display=swap" rel="stylesheet"></link>

export default function App() {
  
  let days = {
    1: 0,
    2: 0,
    3: 0,
    4: 0,
    5: 0,
    6: 0,
    0: 0
  };
  
  const handleChange = (days) => { this.setState(days) }

  return (
    <View style={styles.container}>
      <View style={styles.calApptComponentContainer}>
        <View style={styles.calHeader}>
          <Text style={{ borderColor: "green", borderWidth: 1, flex: 1 }}>
            Tues, Jan 14
          </Text>
          <View
            style={{
              borderColor: "purple",
              borderWidth: 1,
              flex: 1,
              alignItems: "flex-end",
            }}
          >
            <Icon name="calendar-blank" size={30} color="#000" />
          </View>
        </View>
            <WeekdayPicker
              days={days}
              onChange={handleChange}
              style={styles.picker}
              dayStyle={styles.day}
            />
        <View style={styles.calMeetingTimeSelectorContainer}>
          <Text>CalMeetingTimeSelector</Text>
        </View>
        <View style={styles.calFooter}>
          <Text>CalFooter</Text>
        </View>
      </View>
      <Background />
      <StatusBar />
    </View>
  );
}

Am I setting this up incorrectly?