Typically this time frame uses the BBY to specify the year. Since the Battle of Yavin hasn't occurred yet and may never occur. I propose we use the BBG (before the Battle of Geonosis) & ABG (after the Battle of Geonosis).

The year in which the Invasion of Naboo took place would be 10 BBG (Episode 1)
The year in which the Battle of Geonosis took place would be 0 ABG (Episode 2)
The altered events that lead to this RP took place in the year 3 ABG. (altered Episode 3)
The year in which this RP takes place is 8 ABG.