TimeTrex Time and Attendance

I've just setup TimeTrex to evaluate it for our hourly employees, but the thing that has me stumped (if it's even possible) is how to apply our premium differentials. We're a 24x7 shop - 1st shift 7am-3pm, 2nd shift 3pm-11pm, 3rd shift 11pm-7am ... 2nd shift is 1.05X base rate and 3rd shift is 1.10x...