Just checking something with you:
If you have are calculating pension accrual in the year for a DB scheme, is it always going to be the salary as at 5th April used? Are schemes able to use salary from, say, October, for example, instead?
How the scheme calculates the pension entitlement at the opening and closing of the PIP is determined by the scheme rules. They can base accrual on any salary basis they want, from any time period and at any date, as long as it is in the rules of the scheme.