At my airline, which is not a major, there is a seniority list to be considered for command upgrade. On short-haul – besides a minimum amount of hours – there is a requirement of at least 5 years in the company and on long-haul – besides even more hours – the minimum is at least 8 years in the company. In case of need, the time in the company is not a hard requirement as long as you have the minimum hours.