Can we know the exact date of Resurrection? Wikipedia gives two possible dates for resurrection 7 Apr 30 and 3 Apr 33: I wonder why we cannot date the event with accuracy since we know the details : full moon on 14 Nisan. It would seem quite easy , with modern knowledges and techniques, to determine on what year the first vernal full moon took place on 14 Nisan, what are the problems?
It is indeed possible to calculate, within a few hours, the timings of full moons in the first century. Stochastic variations mean we cannot be more accurate.

The question asks whether we can apply the knowledge that there was a full moon on Nisan 14 to narrow down the possible years it could have been. Unfortunately this does not help. This is because Nisan like all Jewish and Islamic months only starts when the new moon is sighted. This means there is always a full moon on, or very close to, Nisan 14. We would be looking for a full moon occuring 14 days after a new moon became visible. Not a distinguishing feature.

Because the Resurrection was Sunday, and the Crucifixion believed to be Friday, this means that we are looking for a year in which the full moon was Thursday or Friday. We know there was a full moon on Thursday evening, April 6th, 30AD; and one on Friday afternoon, April 3rd, 33AD. In other years in the late twenties and early thirties the full moon was on a different weekday.

These dates are calculated according to the Roman calendar (Julian). We cannot say, with certainty, what date in the Jewish calendar, used in the first century,  was the equivalent to a Roman date. In principle these dates should have been Nissan 14. However the start of a month depended on actually seeing the crescent moon, and this depennded partly on the weather and the amount of sand in the air.

Furtermore, although the temple authorities aimed to ensure the Nisan full moon was the first full moon in Spring, there were other considerations. If there was a risk that the Nisan full moon would happen before the equinox they interposed an extra month, making Nisan later. Two other considerations were that the barley and wheat were developing. If they were not Nisan might be postponed leading to the Nisan full moon being the second full moon of Spring. This was because a barley offering was made at Passover time, and a Wheat offering at Pentecost. If the winter weather persisted later than usual Nisan might not be announced at the expected time.

We do not know the exact dates, in Roman terms, on which Passover occurred. We do know there was always a full moon on or close to Nisan 14, but that doesn't help. 

The reason  AD30 and AD33 are the main candidates, rather than nearby years, is purely because the full moon was Thursday evening and Friday afternoon respectively.