Why are Sikh weddings only in the morning and done by 12pm

I attended a family wedding this past weekend, and the schedule was pretty hectic. They had their Lady's Sangeet the night before the Wedding Day. So it was a little tiresome. I asked why are all the wedding so early in the morning, and why can't they be started later in the afternoon (like start at 12pm). I was given a mix of answers from family and from what I found online (or didn't find).