Each Puja ceremony takes about 4 to 5 hours duration. Pujas has to be performing on auspicious days for maximum results. Remember to email the full birth name, day of birth, time if you know (but am or pm will do) place of birth. Have faith and allow the blessing ceremony energy move your obstacles.
Namaste
PS. It is recommended to order the Mercury Puja Ceremony each year due to the fact that each time falls into a different month with a different zodiac sign and will enhance those lessons of that particular zodiac sign to all of us.  Mercury retrograde happens 3 times each year and some zodiac signs get more affected than others depending on each person's charts but as a general rules affects everyone.