Changing the date

We didn't do a survey for our first reunion.
We had it on Saturday after Thanksgiving.
We have nieces and nephews who live out of State and would like to be able to attend. They have children and grandchildren in school. What would be wrong with changing the reunion date to July? Or maybe the first week in August while school is out? Some people think it cannot be changed. Would it really be that critical? If it is we could always change it back. A lot of people cannot come the Sat. after Thanksgiving either. They have their own family plans. Thanks for any feedback you could give. I feel I am being torn between nieces and nephews. I am thinking about sending out a survey with the invitations and tally up the results to be presented at this year's reunion. Thanks.