DaHjaj nom Soppu'
Today they ate quickly. TKD

DaHjaj jI'oj
Today I am thirsty. CK

DaHjaj SuvwI' SoH
Today you are a warrior. PK

DaHjaj SuvwI''e' jIH
Today I am a warrior. TKW

DaHjaj matlh jupna' pIpong
Today we name you a true friend of Maltz. FMC

DaHjaj romuluSngan vIHoHpu'
Today I killed a Romulan. (st.k 6/1997)

nI' DaHjaj
Today is long. (st.k 6/1997)

st.k 6/1997: DaHjaj also behaves as a noun (as opposed to an adverbial element) in such noun-noun constructions as DaHjaj gheD "today prey" or "today's prey", a term often heard in Klingon restaurants with a meaning comparable to "catch of the day".

Examples of timestamps from Okrand's st.k post are:

DaHjaj DungluQ  this noon, today at noon
DaHjaj pemjep   this midday, today in the middle of the day
DaHjaj po       this morning
DaHjaj pem      today's daytime
DaHjaj pov      this afternoon
DaHjaj ram      tonight
DaHjaj ramjep   this midnight, tonight at midnight

All of these forms can be shortened:

DaHDungluQ
DaHpemjep
DaHpo
DaHpem
DaHpov
DaHram
DaHramjep

A common synonym is jajvam, best known from:

Heghlu'meH QaQ jajvam
It is a good day to die. TKW
(or "Today is a good day to die.")