According to Chinese theory, every day is effected by 1 of the power of 5 elements (water, wood, fire, metal and earth). Every person is being influenced by these five elements, some elements coordinate and stimulate the person's energy, the other elements only weigh down.
Its very important to choose good day for important activity like signing contract, starting a construction project or even gambling.
So when you are planning important event do not forget to bring it into correlation with Feng Shui Calendar. Plan your date of engagement or marriage only on favorable for you days, so you will have passion love and trust during whole mutual life.