There is no particular day of the week or year for doing marriage contracts. Rather a person may do his marriage contract on any day he wants, whether it is a Friday or any other day, so long as the reason why he chooses this day is because that is most suitable for him. There is nothing in this matter, in and of itself, that has to do with Sunnah or bid ‘ah.
This is based on the apparent meaning of your question, that you chose Friday – in the first place – then you heard something about it. Based on that, you do not have to change that appointment and there is no innovation involved in that, in sha Allah.
With regard to it being mustahabb to do the marriage contract on that day, and deliberately seeking to do that, this was mentioned by more than one of the fuqaha’ among the followers of all four madhhabs.
Ibn Qudaamah (may Allah have mercy on him) said:
It is mustahabb to do the marriage contract on a Friday. End quote.
Al-Nafaraawi al-Maaliki (may Allah have mercy on him) said:
It is mustahabb for the proposal and the marriage contract to be on a Friday. End quote.
Al-Fawaakih al-Dawaani, 2/11
See also Asna’l-Mataalib by Shaykh Zakariya al-Ansaari al-Shaafa‘i, 3/108; Fath al-Qadeer by Ibn al-Humaam al-Hanafi, 3/189
They quoted as evidence for that the actions of a number of the early generation, including Damurah ibn Habeeb, Raashid ibn Sa‘d and Habeeb ibn ‘Utbah. They also noted that Friday is a blessed day, so there is the hope that Allah will bless the marriage if it takes place on the blessed day; and because it is a noble day and a day of Eid.
It should be noted that the way the fuqaha’ spoke of it was to say that it is mustahabb; they did not say that it is Sunnah, because they knew that encouragement to do the marriage contract on a Friday was not narrated from the Prophet (blessings and peace of Allah be upon him); rather it was narrated from some of the early generation and early fuqaha’, and was based on their own opinions on attaining blessing for the marriage if it coincided with the blessing of Friday, and in the hope that Allah would answer supplications offered on that day.
The fuqaha’ often use the word mustahabb to refer to something for which no particular evidence was narrated. So what is mustahabb in their view is broader in scope that what is described as “Sunnah”, because the latter requires proof that it is indeed narrated from the Prophet (blessings and peace of Allah be upon him) in a saheeh, marfoo‘ hadeeth.
Hence some of the scholars pointed out that we cannot rely upon the description of something as being mustahabb as meaning that it is a proven Sunnah from the Prophet (blessings and peace of Allah be upon him), so that it will not be thought to be Sunnah; rather it should be noted that the issue of it being mustahabb is subject to further discussion.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
I do not know of any Sunnah concerning this. They gave as the reason for that the fact that the latter part of Friday is a time when supplications are answered, so there is the hope that the supplication that is usually offered for blessing for the couple will be answered.
But it might be said: Was it the practice and Sunnah of the Prophet (blessings and peace of Allah be upon him) to seek out this time? If that is proven, then saying that it is mustahabb is acceptable. But if it is not proven, then it should not be taken as a regular practice. Hence the Prophet (blessings and peace of Allah be upon him) used to perform marriages and get married at any time, and there is no proof that he chose any particular time.
Yes, if it happens to take place at that time we say that this, in sha Allah, is a fortunate coincidence, but as for seeking out this time, that is subject to further discussion, unless there is evidence to that effect.
So the correct approach is that whenever it is possible to do the marriage contract, whether in the mosque or at home or in the marketplace or on an airplane and so on, and whenever it is possible to do it, that is fine. End quote from al-Sharh al-Mumti‘, 12/33
To sum up:
So long as you chose that day from the outset, there is nothing wrong with you doing that, and you do not have to change it, and we hope that Allah will bestow upon you the blessing and grace of that day.
And Allah knows best.