Timeline

756 A.D.
Videl is born.
Wait!Videl's older? True or false? Well actually, she'd be a year old than Gohan but since he was in the Time Chamber a year pasted in a day which made him the same if not one year older.

757 A.D. Sometime in May.
Gohan is born.

774 A.D. April 7th
There's a sighting of the Golden Haired Warrior in Satan City.
Gohan goes to Orange Star High School.
He meets Videl.

Gohan meets Bulma at 3 PM.

She works on a transformation suit for him so he can disguise himself when fighting crime.

She finishes at 5 PM.
The Great Saiyaman appears for the first time!

774 A.D. April 8th
Videl discovers that Gohan is the Great Saiyaman.

774 A.D. April 9th
Gohan teaches Videl how to fly.

774 A.D. April 20th
Videl masters the flying technique.

779 A.D. March
Gohan and Videl marry.

779 A.D. Novemeber
Pan is born to Gohan and Videl. Rewind