"mapawDI' wa'maH loSlogh Qoylu'pu'."
Translation:We will arrive at fourteen hundred hours.
The Qoylu'pu' phrase refers to the number of chimes of a bell counting out hours. It's not military time.
We know that Klingons use a twenty-four hour day, as most of the rest of the galaxy: "Klingons have adopted the way most civilized planets in the Galaxy tell time, they have twenty-four hour days." (Conversational Klingon)
We know they use military time like this: wa'maH loS vatlh rep fourteen hundred hours.
We Klingon that the Qoylu'pu' phrase refers to a bell counting the hours.
So, unless Klingon clocks or bell-ringers count out fourteen hours at fourteen hundred hours, this sentence should be mapawDI' cha'logh Qoylu'pu' When we arrive it will be two o'clock. Or you might change that around to wa'maH loS vatlh rep mapaw We will arrive at fourteen hundred hours. But you can't mix the two.
The Qoylu'pu' phrase refers to the number of chimes of a bell counting out hours.
The X-logh Qoylu'pu' phrase doesn't refer to a modern/future-day occurrence, though; it is "based on the way the question was asked long ago, in a time before Klingons traveled around the galaxy and before there was any significant amount of interaction between Klingons and residents of other planets".
The source indicates that the origins of the expression are not fully understood, at least to Maltz. One possible earlier version of the phrase is DaHjaj X-logh Qoylu'pu'., suggesting it (whatever "it" is) may only have been heard once every hour, while another is qen X-logh Qoylu'pu'., suggesting it is rung out X times at X o'clock.
this sentence should be mapawDI' cha'logh Qoylu'pu' When we arrive it will be two o'clock.
I don't believe there's been any indication that Klingons use the 12+12 hours AM/PM system. We know that X-logh Qoylu'pu' "is now also used for the 24-hour system". I think it seems more natural to assume that the X would be the same as in X-vatlh rep, but I can't find any canonical source that clarifies that issue; this would be a good question to put to Okrand directly.