This was meant to have nice inserted pictures and tidy hyperlinks but the forum's being glitchy today. So unfortunately it's going to be a messy post where you're going to have to exercise your tapping fingers and click on the links to the pics to see what I'm referring to. Sorry about that.
In the article recently studied "Do This in Remembrance of Me" (w13 12/15), there is a box on p. 23 giving the date of this year's Memorial and how that date is arrived at.
http://wol.jw.org/en/wol/d/r1/lp-e/2013926
IMAGE (scroll past the gap *sigh*) - http://i1175.photobucket.com/albums/r632/AnnOMaly/Nisan%202014/NewmoonNisan2014_WT_zps22894423.jpg
They say it's doubtful that the new crescent will be seen on March 31 (which would mark Nisan 1) and will more likely be seen the following evening on April 1.
The Planetary, Stellar and Lunar Visibility program (Google for more info.) indicates otherwise.
So does the Torah Calendar site:
Granted, the new crescent is at the limits of naked-eye visibility, but its orientation (right above the Sun rather than being angled to the side and low to the horizon) and at 1% illumination should make it theoretically possible to see under optimum conditions just before it sets on March 31.
If so, Nisan 14 would occur at sunset, Sunday April 13, rather than the WT's Monday April 14.
What is certain, however, is that the WT got 'Jerusalem time' wrong for astronomical new moon on March 30. Jerusalem switches to Daylight Saving Time on March 28 this year, as a look on the timeanddate site will tell you.
IMAGE - http://i1175.photobucket.com/albums/r632/AnnOMaly/Nisan%202014/Jerusalem_DST_2014_zpsa5e1f319.jpg
And the same site says that new moon actually occurs at 9.45 p.m. Jerusalem time. Oops.
http://www.timeanddate.com/calendar/moonphases.html?n=110
Does the Writing Department really trace all things accurately - "even insignificant details"? - http://wol.jw.org/en/wol/d/r1/lp-e/302011018#p11
Hmm.