Matthew’s “Days”
There are seven evenings in Matthew’s Gospel (8:16; 14:15, 23; 16:2; 20:8; 26:20; 27:57).
Not every instance of “it was evening” begins a new section — 16:2 and 20:8 certainly don’t! — but the number of evenings does interest me, suggesting as it does that the reference to evening ends a day or (as in Gen 1) begins a new day.
In turn, and that would suggest that there may be eight “days” in Matthew, the eighth being the day of resurrection, beginning with 27:57, which certainly seems fitting.
Nevertheless, as I mentioned above, 16:2 and 20:8 don’t seem to fit into any sort of seven- or eight-day pattern. Still, if you happen to see some such pattern or know of an essay where someone works this out, I’d be glad to see it.
[Update, March 15, 2016: It turns out that Peter Leithart has an essay on exactly this topic!]