Calculation to Sort by Date (Oldest to Newest) and then Number (Lowest to Highest)

Hello,

I am making an overtime distribution app, the way it is broken down is the OT wheel app is where you input the OT and the Employee Profile where the OT is added up for the year and their seniority date is listed. What I want to do is create a reference ID for the employee Profile that has their current OT, their name, and their Seniority date (MM/DD/YYYY). Then in the OT Wheel a calculation that will sort by Seniority date (Oldest to Newest) when the current OT number is 0. The secondary sort will be by the OT hours (Lowest to highest) once OT starts to accumulate for each person. Any guidance would be much appreciated!