I've had my own continuity for a few years now and I find it works best if I personally ignore an gaffes by writers and chalk it up to, "well, it's a comic book."
Bruce is Batman at 25. He adopts Dick when Dick is 13. Dick becomes Nightwing at 18, at which point Bruce is 31. Jason is killed when Bruce is 33/34, Tim adopts the Robin mantle when Bruce is 34. Damian becomes Robin when Bruce turns 39. That would put Dick around 27/28 and Tim around 18/19 right now.
It works in my brain.
I've got a continuity that is the offspring of a greasy orgy between old and new DC.
Immediately before #1- Batman Inc disbanded
6 months ago- Batman Inc founded
18 months ago- Dick becomes Batman
20 months ago- Damian appears
2 years ago- Jason resurfaces
3 years ago- Jason dies, months later Tim becomes Robin
4 years ago- Jason becomes Robin, Dick becomes Nightwing
7 years ago- Dick becomes Robin, Batman given signal from Gordon
9 years ago- Bruce adopts "Batman" persona
10 years ago- Bruce attempts to fight crime, using those gadgets, Damian is born
11 years ago- Bruce bangs Talia
14 years ago- Bruce Wayne disappears
17 years ago- Tim Drake is born
20 years ago- Jason Todd is born
23 years ago- Dick Grayson is born, Thomas & Martha killed
31 years ago- Bruce Wayne is born