Most league rules don't allow re-schedules other than for weather or USTA post season conflicts because of the problems that always come up. Typical scenario is as follows:
Captain A can't field a team this Saturday due to various player issues, so Captain A asks Captain B for a re-schedule. Captain B politely says "I need to check my teams schedules but I'll see what I can do and get back to you." Captains B finds out that a re-schedule is going to be a nightmare due to her players tight schedules, so Captain B contacts Captain A in a timely manner and says "I'm sorry but I can't do it. We need to play the scheduled day." At that point Captain A should simply say "Thank you for checking. I understand." But what often happens is Captain A goes ballistic and berates Captain B for being unsportsmanlike, yada, yada, yada. Then they contact the LC who usually says go by the rules. Then Captain A yells at the LC for "siding with Captain B". This happens so often that most LC's just put in their local rules that re-scheduling is not allowed.