{Know perfectly} (akrib(9373) oidate). Accurately know, not
"the times and the seasons," but their own ignorance. {As a thief
in the night} (h(9373) klept(8873) en nukti). As a thief at night,
suddenly and unexpectedly. Reminiscence of the word of Jesus ( Mt
24:43  Lu 12:39 ), used also in  2Pe 3:10  Re 3:3  16:15 .
{Cometh} (erchetai). Prophetic or futuristic present tense.