My college's PHC has Bid Day on a Sunday every year. We usually have all of the NMs meet up at 12pm, go through a 1hr long Rho Gam Reveal/speech from the Dean/misc information. Then, we open up bids, run to meet our chapter's Rho Gams, and take lots of photos before running home.
Once we run to the chapter, there's usually about 30 mins - 1hr of time out on the lawn, meeting and greeting people and taking lots of photos. Women also meet their Bid Day buddy and get a Bid Day shirt during this time. In my chapter, we then headed inside to grab food and introduce everyone for an hour. Then, we had a meeting to sign forms and inform NMs of the details for the formal pledging ceremony later that evening. (While they were doing that, actives were talking and setting up things for formal pledging.) Usually, we were done by 3PM and had everyone back for formal pledging about 2-3 hours later. Afterward, we'd have dinner and do an activity together until about 9-10pm. The year I pledged, we went bowling together. My senior year, we played board games and ate cookies/treats.
As Titchou already noted, the culture of each chapter and school is always a little different. Other chapters at my school did crafting activities, visited an indoor trampoline place, or even had another event later in the week to bond with NMs. Find what works best for your school and all members' time commitments. Plus, it never hurts to ask the chapter what they want to do and get some input from your sisters.
