The 2824 has an integrated date jumper/spring. It could be that this was bent during reassembly?
You need to uncase the movement, remove the hands/dial and wind the watch thru the date-change, watching the interaction of the date wheel, calender driving wheel and the jumper spring.
One more thing you can try before you do that, try to bring the date into alignment using pegwood thru the date window..gentle pressure as the date-wheel is quite fragile. If this gets the date wheel in alignment, then check the daywheel track opposite the jumper... if it is worn you need to dress it and maybe get a new date wheel.
2824 parts are quite common... do you have a spare movement? Off the top of my head.. 2834/2836 will work... I believe many others as well... you could swap out the date wheel and maybe the jumper and see if that fixes things but as others have mentioned, its probably the jumper spring thats the problem if it was fine before.
Finally, eyeball the dial feet when you remove it.. if it was not removed 'squarely' off the dial, the feet may get bent.. dont think this would affect the alignment much though.