Time based user greetings (Good Morning, Afternoon, Evening) using moment.js

moment-greetings.js

getGreetingTime = (currentTime) => {
  if (!currentTime || !currentTime.isValid()) { return 'Hello'; }

  const splitAfternoon = 12; // 24hr time to split the afternoon
  const splitEvening = 17; // 24hr time to split the evening
  const currentHour = parseFloat(currentTime.format('HH'));

  if (currentHour >= splitAfternoon && currentHour <= splitEvening) {
    // Between 12 PM and 5PM
    return 'Good afternoon';
  } else if (currentHour >= splitEvening) {
    // Between 5PM and Midnight
    return 'Good evening';
  }
  // Between dawn and noon
  return 'Good morning';
}

Inspired by https://gist.github.com/James1x0/8443042

Instead of moment.js currentTime.format('HH') you could use new Date().getHours()