We celebrate the Savior’s birth on December 25th but there is considerable debate regarding when Christ was born (not that Wikipedia is authoritative but see for example: http://en.wikipedia.org/wiki/Chronology_of_Jesus#Day_of_birth). From the Book of Mormon we gain clarity.
“And now it came to pass, if there was no mistake made by this man [Nephi] in the reckoning of our time, the thirty and third year had passed away; And the people began to look with great earnestness for the sign which had been given by the prophet Samuel, the Lamanite, yea, for the time that there should be darkness for the space of three days over the face of the land… And it came to pass in the thirty and fourth year, in the first month, on the fourth day of the month, there arose a great storm, such an one as never had been known in all the land [heralding the Savior’s death].” (3 Nephi 8:2,3,5).
When the sign was given of Christ’s birth, the Nephites set that date as the beginning of their new calendar. So given that the calendar was accurate (it’s possible that it was off by a few days or even more over the course of 33 years), Christ died on the 4th day of the 1st month of the 34th year. Depending on how that statement is interpreted, it means the Savior died right around (or on, if there are some inaccuracies with that Nephite calendar, which there likely were) His 33rd birthday (although it could be understood to be that He had just turned 34 if the 34th year = 34 Nephite AD rather than being the start of Savior’s 34th year – counting from 0 – which would be 33 Nephite AD). Having just turned 33 (rather than 34) gives the Savior about a 3 year ministry (ages 30, 31, and 32 – see Luke 3:23), which is generally accepted as the length of His ministry, although there is some debate regarding the length of Christ’s ministry (but I will not cover that here).
But from the Book of Mormon, we at least have the answer to when Christ was born – at the same time of year at which He died, which was at the time of Passover (roughly corresponding with our late March to early April, typically when we celebrate Easter). The symbolism of all of this is rich – the First Born Pascal Lamb, whose atoning blood allowed for the passing over (forgiving) of sins, entered the world in blood and spirit and shed His blood and suffered in and gave up His spirit at the time that Jews celebrated the salvation of their first born sons and their salvation from captivity in Egypt. Christ is the One who died to free the captives, releasing them from prison like the Israelites passing through the Red Sea out of captive Egypt. I think it would be even more symbolic (but ultimately unnecessary) if the Savior was resurrected on His birthday.
None of this really matters in the end but if the Nephite calendaring system is accurate (it probably was quite good), the Savior’s birth occurred at the same time of year as His death, right around the beginning of April.