Although we don’t know for sure, many scholars date Jesus’ death and resurrection to the year 30 CE. If this is true, what is the most likely day and date for Passover (and the crucifixion) in that year?
Before the Second Temple was destroyed in 70 CE, the beginning of each month was determined by observation of the crescent moon. The beginning of the year, Aviv (אביב), was determined by the state of growth of the barley crop. It usually reaches the aviv stage in March or April each year. Because weather plays a big role in determining both the beginning of the month and the year, we can’t know for certain when these determinations were made in the year 30.
The new moon in March that year occurred on Wednesday, March 22nd at 7:50 PM (http://www.timeanddate.com) by the Julian calendar. Since sunset is about 6:00 PM it could not be seen that night. The next night (Thursday) the Moon would be about 22 hours old. The record for seeing a new moon with the unaided eye is about 15 hours old (http://www.earthsky.org/faq/young-moon-visibility) so it is fairly likely that it would be spotted that night, weather permitting. If it was seen Thursday night after sunset, the first day of the month of Aviv (Nisan) would be Friday.
If all of these assumptions are true, then Passover, occurring on the 14th of Nisan, would have been on Thursday, April 6th 30 CE.