In greece, we have a word which describes the time of day from around 1.00 pm to roughly 4.00 pm. And another word for the time of day between lets say 5.00 pm to around 7.30
pm.

What does the {DungluQ) actually describe ?

DungluQ is noon, or 12 pm.

In English we have the words morning, afternoon, evening, and night, which aren't rigidly defined by clock-time. A common understanding is that morning is from dawn to 11:59 am; afternoon is from 12:01 pm to the beginning of twilight; evening is from the beginning of twilight to the end of dusk; night is everything else. Evening, in particular, changes in meaning depending on the speaker and the context; it can often cover what might otherwise be considered the late part of the afternoon.

Klingon has the following words, which may or may not correspond to the English terms:

pem daytime
jajlo' dawn
po morning
DungluQ noon
pov afternoon
choS twilight
tlhom dusk
ram night
ramjep midnight

-- 
SuStel
http://trimboli.name