TIME is not the correct answer. This can easily be demonstrated. For example, how much TIME is required to hold a NB captain position at US, HP, UA, DL, WN, CO, AA, AS or the rest. Is the same amount of TIME required to hold that left seat at each of the above carriers the same and has that TIME requirement been consistent each of the last 30 years? How much TIME is required for a pilot at any of these airlines to get to a WB? When will a US, HP, WN, AS or other pilot be guaranteed an opportunity to fly a B747, a B787, a A340, or an A380? If TIME is the single factor then one should be able to predict with absolute certainty when he will move from the right seat to the left, and when he will move from NB to WB and then from WB to superjumbo, right?
Is that how this TIME= SENIORITY system works or are there factors other than TIME that determine position/status? If other factors go into a person's seniority and thus the seat position that he is able to maintain, then your repeating TIME over and over again reveals an ignorance of the facts.