It sounds like its a direct debit, which should be no problem to change.
Every loan has a required monthly repayment amount and date. So to make sure it's not behind it may require the extra week to get it ahead.
HTH - I used to to work in a bank.
the next payment is due on the 14th and it's ahead already so there is money there for it. I'm hoping to change the payment cycle with the next payment to be on the 19th then go forntnightly from there.