What is a “Black Moon”? According to a commonly used definition a “Black Moon” is any month during which there are 2 new Moons, or even more rare a month with no new Moons. Obviously the Moon at new phase is in the direction of the Sun and therefore is not visible at all, perhaps given rise to the name “Black Moon” because the illuminated side of the Moon is toward the Sun, and the unilluminated, dark, side of the Moon is toward the Earth.
On Thursday August 1st the first of two new Moons this month will rise about 30 minutes after the Sun rises and will not be visible as it follows the Sun across the sky to moonset about 1 hour after sunset local time. On August 30th the second new Moon of the month will follow a similar pattern as the new Moon on August 1st in that this new Moon also will not be visible as it too follows the Sun, setting within an hour after the Sun sets. Graphics below are set for the time when the new Moon transits, or is due south, and is mid-way between rising and setting.
What makes the term “Black Moon”, in this instance, interesting is that depending on your time zone the “Black Moon” may have been either July or August depending on your local time zone for the new Moon of July 31st or August 1st.
New Moon Dates and Times (using UT) July 2 19:16 UT August 1 3:12 UT (July 31 10:12 pm CDT) August 30 10:37 UT