Originally Posted by flensr

Years of Service Pay rates are tied to date of hire. It'll be printed on your ID badge if you forget
The contractual pay scale increases for everyone are effective on the anniversary date specified in the contract. But movement up the pay scale happens on date of hire.

There is some weirdness due to how our first monthly paycheck is an advance and the rest of the month is paid out on the 20th of the following month. For example...
Let's say you were hired in June. That means your June 5 paycheck which is an advance on your June pay, will reflect your next higher pay rate. But your June 20 paycheck which is really when you get your pay for May, will reflect the previous lower payscale since the June 20 paycheck accounts for work done in May. Then both July paychecks will reflect the new higher pay rate.