Know-How Exchange : Advertising/PR

We are trying to organize an event management seminar and want to attract as many visitors as possible. Our targets are agency and marketing directors plus project and event managers (pros who organize events). It is going to be a day and a half long seminar starting in the afternoon with social activities and a party in the evening. It will then continue the next day with lectures and workshops. We know the business is hectic during the week so were thinking of starting the social on Sunday afternoon and lectures on Monday. However, we are afraid it will turn people off because we would be cutting into family time. Is Sunday-Monday a good combination or should we consider another one? We need the timing to be optimal, because we are betting our business on it.