DCA is usually 10-6 M-Th, DL 10-8 M-Th. Fri, Sat and Sun later. It varies. Usually DL won't close before 10 with Sat generally being the latest day. I think it also opens as early as 9 on sat (and maybe Sun)
DCA on the weekends is usually open until 9 with occasionally a 10pm closing. The only time it generally closes later than 10 is New Years Eve.
DCA will only have longer hours than DL if there is something special going on at DL and it is closing early.
Electric parade will probably be on the weekends. Fantasmic and fireworks may or may not be on the weekends. The past few years they've generally either had fireworks or fantasmic, on weekends, but rarely had both. Really there's no way to tell.