If you start in June, pilots in your class that have the time will be holding captain in Aug-Oct range. Since you won't have the time, pilots after you will get the upgrade slots. It will take about a year for you to get up to 1000 hours and by then all the more senior pilots to you, who had to bypass due to low time, will take the regular upgrade slots for regular attrition. You're looking at a 2-4 year upgrade because of these factors.