Column

Sunrise through 11 am　 "Good morning" = “Ohayou gozaimasu”
11 am to 5 pm　 "Hello" = “Konnichiwa”
After 5 pm "Good evening" = “Konbanwa”

【Example】

In the morning, when you go to work, you usually say "Ohayou gozaimasu".
If you go into work at any other time, it is common for you to say "Otsukaresamadesu” (thanks for your work)
When you go home, you should say, "Otsukaresamadeshita.”(Thank you for your hard work ) or "Osakini shitsureishimasu"(I am leaving now).