Who knows why Jesus died at the particular time of the day he died (at about 3:00 in the afternoon)? The answer is below, but no fair peeking before you make a guess, or before you research it. 

Matt 27:50-56

I. The manner how he breathed his last (v. 50); between the third and the sixth hour, that is, between nine and twelve o'clock, as we reckon, he was nailed to the cross, and soon after the ninth hour, that is, between three and four o'clock in the afternoon, he died. That was the time of the offering of the evening sacrifice, and the time when the paschal lamb was killed; and Christ our Passover was sacrificed for us and offered himself in the evening of the world a sacrifice to God of a sweet-smelling savour. It was at that time of the day, that the angel Gabriel delivered to Daniel that glorious prediction of the Messiah, Dan 9:21,24, etc. And some think that from that very time when the angel spoke it, to this time when Christ died, was just seventy weeks, that is, four hundred and ninety years to a day, to an hour; as the departure of Israel out of Egypt was at the end of the four hundred and thirty years, even the self-same day, Ex 12:41.
(from Matthew Henry's Commentary on the Whole Bible: New Modern Edition)