npm install react-native-datetime --save

...
include ':react-native-datetime'
project(':react-native-datetime').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-datetime/android')

...
dependencies {
  ...
  compile project(':react-native-datetime')
}

import com.keyee.datetime.*; // <--- import
 
public class MainActivity extends ReactActivity {
 ......
 
 /**
  * A list of packages used by the app. If the app uses additional views
  * or modules besides the default ones, add more packages here.
  */
  @Override
  protected List<ReactPackage> getPackages() {
   return Arrays.<ReactPackage>asList(
    new RCTDateTimePickerPackage(this), // <------ add here
    new MainReactPackage());
  }
}

import com.keyee.datetime.*; // <--- import
 
public class MainActivity extends Activity implements DefaultHardwareBackBtnHandler {
 ......
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  mReactRootView = new ReactRootView(this);
 
  mReactInstanceManager = ReactInstanceManager.builder()
   .setApplication(getApplication())
   .setBundleAssetName("index.android.bundle")
   .setJSMainModuleName("index.android")
   .addPackage(new MainReactPackage())
   .addPackage(new RCTDateTimePickerPackage(this))       // <------ add here
   .setUseDeveloperSupport(BuildConfig.DEBUG)
   .setInitialLifecycleState(LifecycleState.RESUMED)
   .build();
 
  mReactRootView.startReactApplication(mReactInstanceManager, "ExampleRN", null);
 
  setContentView(mReactRootView);
 }
 
 ......
}

<DateTimePicker ref={(picker)=>{this.picker=picker}}/>
...
this.picker.showDatePicker(...)
this.picker.showTimePicker(...)
this.picker.showDateTimePicker(...)

'use strict';
 
var React = require('react-native');
var {
  StyleSheet,
  TouchableOpacity,
  View,
  Text,
} = React;
 
var DateTimePicker = require('react-native-datetime');
var Button = require('@remobile/react-native-simple-button');
 
module.exports = React.createClass({
  getInitialState() {
    return {
      date: new Date(),
    }
  },
  showDatePicker() {
    var date = this.state.date;
    this.picker.showDatePicker(date, (d)=>{
      this.setState({date:d});
    });
  },
  showTimePicker() {
    var date = this.state.date;
    this.picker.showTimePicker(date, (d)=>{
      this.setState({date:d});
    });
  },
  showDateTimePicker() {
    var date = this.state.date;
    this.picker.showDateTimePicker(date, (d)=>{
      this.setState({date:d});
    });
  },
  render() {
    return (
      <View style={styles.container}>
        <Text style={{textAlign: 'center'}}>
          {this.state.date.toString()}
        </Text>
        <View style={{height:40}} />
        <Button onPress={this.showDatePicker}>showDatePicker</Button>
        <View style={{height:40}} />
        <Button onPress={this.showTimePicker}>showTimePicker</Button>
        <View style={{height:40}} />
        <Button onPress={this.showDateTimePicker}>showDateTimePicker</Button>
        <DateTimePicker ref={(picker)=>{this.picker=picker}}/>
      </View>
    );
  },
});
 
var styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    paddingTop:20,
  },
});