Showing Morning, afternoon, evening, night message based on Time in java

You should be doing something like:

Calendar c = Calendar.getInstance();int timeOfDay = c.get(Calendar.HOUR_OF_DAY);if(timeOfDay >= 0 && timeOfDay < 12){    Toast.makeText(this, "Good Morning", Toast.LENGTH_SHORT).show();        }else if(timeOfDay >= 12 && timeOfDay < 16){    Toast.makeText(this, "Good Afternoon", Toast.LENGTH_SHORT).show();}else if(timeOfDay >= 16 && timeOfDay < 21){    Toast.makeText(this, "Good Evening", Toast.LENGTH_SHORT).show();}else if(timeOfDay >= 21 && timeOfDay < 24){    Toast.makeText(this, "Good Night", Toast.LENGTH_SHORT).show();}

For anyone who is looking for the latest Kotlin syntax for @SMA's answer, here is the helper function :

fun getGreetingMessage():String{    val c = Calendar.getInstance()    val timeOfDay = c.get(Calendar.HOUR_OF_DAY)    return when (timeOfDay) {           in 0..11 -> "Good Morning"           in 12..15 -> "Good Afternoon"           in 16..20 -> "Good Evening"           in 21..23 -> "Good Night"           else -> "Hello"      }    }

I would shorten your if/elseif statement to:

String greeting = null;if(hours>=1 && hours<=12){    greeting = "Good Morning";} else if(hours>=12 && hours<=16){    greeting = "Good Afternoon";} else if(hours>=16 && hours<=21){    greeting = "Good Evening";} else if(hours>=21 && hours<=24){    greeting = "Good Night";}Toast.makeText(this, greeting, Toast.LENGTH_SHORT).show();