As from 6 April 2019 (please note, that's next year!) pay slips will get sexier. For those whose pay varies according to the time worked, the pay slip will have particularise the total number of hours worked by way of a single aggregate figure or separate figures for different rates of pay. The idea is to assist you to identify underpayment, whether it be less than the minimum or living wage or the entitlement under your contract. And the obligation to provide a pay statement will be extended to all workers and not just employees.
If you don't believe me, go to the Employment Rights Act 1996 (Itemised Pay Statement) (Amendment) Order 2018 SI 2018/147 and the Employment Rights Act 1996 (Itemised Pay Statement) (Amendment) (No 2) Order 2018 SI 2018/529. But not in work time!!!