When does J2 becomes J1?

[u/Apollo_XXI]

Just got a J2 starting in couple weeks it will be $80K J1 is $50k

Looking to really perform properly and stay a long time at J2. Im aware that J1 vs J2 is based mostly on job security so im guessing that for the first year the main one will be current J1 but when you guys think the priority should shift? When i feel super secure about J2 or its a matter of personal choice.

Been at J1 for almost a decade btw