there is a problem for you as tomorrow is the next morningThere is a problem with using these types of verses to prove that the day starts in the morning. Does "Tomorrow" mean the next day (i.e. if today is Tuesday, Tomorrow is Wednesday), or does it mean "the next morning." This is made more complicated by the fact that we are talking about ancient Hebrew, Aramaic or Greek, while we are usually looking at translations.
already posted some historical sources in this thread...the when the whys are discussed as well...There is also a historical issue here. You are postulating that in the first century AD Jews started counting days at sunrise. Today we start our days at sunset. This is a huge change. When did it happen? Why? Where is some mention of this in Jewish sources? Roman sources? Church sources?
Speaking of which- when does the traditional Christian liturgical day start?
Interesting they admit following "jewish custom" and not biblical...it's ok peer pressure can be called sacred tradition but if not supported biblically it remains man's tradition