day = new Date()
hr = day.getHours()

if ((hr==0) || (hr==1) || (hr==2) || (hr==3))
document.write("Late night greetings ")

if ((hr==4) || (hr==5) || (hr==6) || (hr==7) || (hr==8) || (hr==9) || (hr==10) || (hr==11))
document.write("Good morning ")

if ((hr ==12) || (hr==13) || (hr==14) || (hr==15) || (hr==16) || (hr==17))
document.write("Good afternoon ")

if ((hr==18) || (hr==19) || (hr==20) || (hr==21) || (hr==22) || (hr==23))
document.write("Good evening ")