The Chinese believes marriage in a Widow Year is inauspicious.
To know what is a Widow Year, one needs to appreciate two types of calendars: the solar calendar (阳历) and the lunar calendar (农历). The solar calendar is based on the movement of the earth around the sun. The lunar calendar, on the other hand, is based on the movement of the moon around the earth. The first day of the solar calendar is known as Li Chun (立春) which falls mostly on 4 February. The first day of the lunar calendar is the first day of the lunar year which is also the lunar Chinese New Year (正月初一). The difference in the time cycle of the two calendars means that the first days of the two calendars rarely occur on the same day. Whenever Li Chun occurs before the first day of the lunar year, the lunar year would not have a Li Chun. The absence of Li Chun in a lunar year is known as a Widow Year.
For example, for the lunar year 2016, Li Chun fell on 4 February 2016; while the first day of the lunar year was on 8 February 2016. This means the 2016 lunar year did not have a Li Chun. Since there was no Li Chun, the 2016 lunar year was a Widow Year. The Widow Year is not a rare occurrence. If one were to look up the thousand year calendar (万年历), you would find that Widow Year occurs quite frequently.
For the lunar year 2017, Li Chun fell on 3 February 2017 and the first day of the lunar year fell on 28 January 2017. This means Li Chun occurred after the first day of the lunar year. This also means that the 2017 lunar year had a Li Chun and was not a Widow Year.
The name Widow Year came about because superstition has it that a woman who marries in a Widow Year will bring pre-matured death to her husband. It is for this reason that a lunar year with no Li Chun is called a Widow Year. From a Chinese metaphysical prospective, the absence of Li Chun in a lunar year, which is purely due to a difference in the time period between the two calendars, should not have any bad influences on people marrying in a Widow Year.
For those interested in auspicious dates and hours for marriage, please see Good Wedding Date.