Eid Al Fitr is one day and Eid Al Ad’ha is four days! Therefore, they can make their celebrations in these days!

I have a question regarding eid party. Some one I know is planning on doing an eid party but not on the day of eid, as some family members won’t be able to attend the party as its during the week in shaa Allah, so they are planning on doing it on the weekend. Also they are planning to do a theme eid party. Is that permissible?