The significance of this day In the Tonalpohualli, the sacred Aztec calendar, this day (Tuesday, July 28, 2015)

Aztec and Maya Calendar

http://www.azteccalendar.com/

In the tonalpohualli, the sacred Aztec calendar, this day (Tuesday, July 28, 2015) is:

Tonalli: day

Trecena: 13-day period

Xihuitl: solar year

The significance of this day

Day Atl (Water) is governed by Xiuhtecuhtli, God of Fire, as its provider of tonalli (Shadow Soul) life energy. Atl is a day for purification by subjecting oneself to the ordeal of conflict. It is a good day for battle, a bad day for rest. Water brings out the scorpion, who must sting its enemies or else sting itself. Atl is the day of the holy war, which is always a battle with one's own enemies within.
The thirteen day period (trecena) that starts with day 1-Miquiztli (Death) is ruled by Tonatiuh. This trecena signifies the vast cosmological forces at play in the lives of human beings. These 13 days are all influenced by transformative powers of unknown dimension, origin and intent. The days of this trecena often pass by unnoticed since they are not remarkable until the elementals turn their attention to this place, the first of the thirteen skies; when this occurs, though, the whole of the world changes. It is during these days that the song of the Old Ones may best be heard. These are good days to fulfill old obligations; bad days to go back on one's word. http://www.azteccalendar.com/