Based on western astrology, this piece is written for those of you who have at least some knowledge of astrology and chart basics, as selecting a date and time for that all important wedding event requires the use of an astrological calendar Muhratm for Marriage or an ephemeris (a manual that provides the exact location and degree of all the planets presently, as well as in the past and future). A seasoned astrologer, who can further interpret your charts, is invaluable, but if that’s not possible, have on hand:
Firstly, the very best months to enter into matrimony are either April/May or even better, September/October. More simply, when the Sun is transiting through the sign Taurus or Libra, both of those planets being ruled by Venus, the time is right to initiate love and partnership events. A calendar must be consulted here as each year the Sun begins transiting Taurus anywhere between April 18th-22nd through May 18th-22nd, likewise, the Sun begins transiting Libra between September 18th-22nd through October 18th-22nd; each year it can be a different starting and ending date so checking the calendar is paramount! Marriages performed when the Sun is in Libra are best as Libra is the traditional sign of couples and marriage partners.
Next, check what sign the Moon is transiting for a chosen day. Again, if it is transiting Libra or Taurus (as it will do at some point each month), that is best, but it's tricky as the Moon only transits a sign for 2.5 days; it moves quickly onto the next sign therefore diligence is required to know its position. A waxing Moon (increasing toward the Full Moon) is considered more advantageous than a waning one (decreasing towards New Moon) but avoid the exact New Moon (wait at least 12 hours after).
Also, pay attention to a Void-of-course Moon (meaning the Moon will not make further aspects to any planets until after it leaves the sign it is transiting) as anything initiated during a Void Moon rarely brings the desired result. An astrological calendar will indicate any Void Moons for a given day (you will see a symbol resembling the Moon and "V/C" beside it) as well as the time it goes Void and when it enters the next sign.
The previous step mentioned "aspects". These are angles that planets make to each other that are determined to be deleterious or beneficial. Again, on the astrological calendar, you will see symbols such as a square, meaning that the Sun, Moon or planets are 90 degrees from each other and that is probably the worst aspect for a ceremony. Look instead for small triangle symbols that represent 120 degrees (also known as a "trine" aspect; these are very good).
Avoid setting a date for when the Moon is transiting Scorpio or Capricorn. With Scorpio, there will tend to be power issues and secrets between two people. With Capricorn, it will be more like a business arrangement than a marriage.
Regarding Step 3: A further note on and example of Void Moons: They are not beneficial for shopping excursions as you'll rarely be satisfied with your purchases, however, it is good if you are opting for nothing to occur, such as mailing your tax return so that it won't be audited. It’s considered a spiritual time to step back, reflect, and finish old business rather than initiating decisive new action.
There’s much more to know with such a huge subject as astrological compatibility and I've just scratched the surface. Ideally, you can consult an astrologer who will examine not only what's going on in the sky that day but will combine your charts (called “synastry”) for even more precision in determining your future life together.