activity_main for tutorial https://youtu.be/BV3ijYdVOfI

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.airbnb.lottie.LottieAnimationView
        android:id="@+id/lottieImage"
        android:layout_width="match_parent"
        android:layout_height="460dp"
        android:layout_alignParentTop="true"
        android:layout_centerInParent="true"
        android:layout_marginTop="-64dp"
        app:lottie_autoPlay="true"
        app:lottie_fileName="events.json"
        app:lottie_loop="true" />

    <cn.iwgang.countdownview.CountdownView
        android:id="@+id/countdownView"
        style="@style/CustomFont"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/lottieImage"
        android:layout_centerInParent="true"
        android:layout_marginTop="-64dp"
        app:isHideTimeBackground="false"
        app:isShowDay="true"
        app:isShowHour="true"
        app:isShowMillisecond="true"
        app:isShowMinute="true"
        app:isShowSecond="true"
        app:isTimeTextBold="true"
        app:suffixDay="d"
        app:suffixGravity="bottom"
        app:suffixHour="h"
        app:suffixMillisecond="ms"
        app:suffixMinute="m"
        app:suffixSecond="s"
        app:suffixTextColor="#000000"
        app:suffixTextSize="12sp"
        app:timeBgColor="@color/colorAccent"
        app:timeBgRadius="4dp"
        app:timeTextColor="#FFFFFF"
        app:timeTextSize="32sp" />

    <TextView
        android:id="@+id/textViewTop"
        style="@style/CustomFont"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/countdownView"
        android:layout_centerInParent="true"
        android:layout_marginTop="32dp"
        android:fontFamily="@font/poppins"
        android:text="Countdown to New Year"
        android:textSize="16sp" />

    <TextView
        android:id="@+id/textViewContent"
        style="@style/CustomFont"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/textViewTop"
        android:layout_centerInParent="true"
        android:textSize="28sp"
        android:textStyle="bold"
        tools:text="DatePicker" />


    <Button
        android:id="@+id/btnDatePicker"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_margin="32dp"
        android:background="@drawable/rounded"
        android:text="Date Picker"
        android:textColor="#fff" />

</RelativeLayout>