Marriages pretty much occur on schedule of the Vimshottari dasha. It is actually not possible to experience a marriage unless the planets are lined up correctly. (Humans don't have the power to control major life events, regardless of what we learn in schools!)
The benefit of Astrology in the modern age is not so much “marriage insurance” via ritual protection of the planets (which certainly used to be Astrology’s central function) but rather mental advantage of knowing when these key life events are most likely to occur. (The only exception is the negative "warning function that a Rahu bhukti is likely to signal a crazy, exotic marriage... which one might wish if karmically possible to decline!)
First marriage occurs during the bhukti of the proper lord plus a gochara Rahu-Ketu contact point. Bhukti of the subsequent navamsha lords with corresponding Rahu-Ketu transits brings subsequent marriages. A more-or-less auspicious day or month within the destined bhukti may be chosen by the marriage partners or their parents, but the timing of marriages is rather a karmic affair, with larger forces enforcing the schedule.
Why is it important to have an auspicious day and time for marriage? The small choices we can make within the greater karmic framework, as to choosing an auspicious day and location, are very beneficial to the spiritual well-being of the partners joined in the holy ceremony of marriage. Certainly it is not possible that our small human choices can override the greater plan, but in seeking to choose the most harmonious conditions we are expressing a higher consciousness and a desire to work hand-in-hand with the divine, which is always a helpful attitude to sustain every day of a working marriage.
Higher consciousness partners, who consider themselves bound to each other through the divine, will generally enjoy their marriages much more than those bound to each other in order to satisfy parents, religion, or government. So choosing an auspicious day and inviting our God and spirits to be present at the joining ceremony is a powerful evidence of the partners' mutual desire for a long and "fruitful marriage.
Proper time for marriage ceremony
Celebrating marriage is auspicious when the Sun is in the signs of
· Taurus and
1) If the Sun is in the sign of Gemini, then marriage maybe celebrated in the month of Ashadha
Note- it is only from the Pratipada (the first Tithi of the month) to the 10th Tithi in the Shukla Paksha or the Bright Half of the month.
2) If Sun is in sign of Scorpio marriage may be celebrated in the month of Kartika.
3) If Sun is in sign of Capricorn, marriage may be celebrated in month of Pausha.
4) If Sun is in sign of Aries, marriage may be celebrated in the month of Chaitra.