People are muddling how DDs and Standing Orders work and their purpose…..and which should be adjusted to arrive ahead of time and which will happen after time, if a usual payment date falls on a weekend or BH.
Standing orders are used to pay people and organised by the person paying. Typically wages are paid by SO. If you owe money for anything which has a date, if you pay by SO it is your responsibility to make sure the money is received on or before the due date. This is why is you are paid by SO, your company will pay you AHEAD of pay date if the usual date falls at weekend or BH. It would not be acceptable for a firm to pay workers 2 days late due to weekend or BH. It is not acceptable to pay rent late for same reason. Wages or rent are the individual’s incomes and they need to know they will have the money by the date it is due.
DDs are taken by the receiving company. The company sets them up. Here, they take the money on the due date or the NEXT available working day. This is why DDs for council tax etc may go out later if there is a weekend or BH. The company who receives money in this way KNOWS the DD system doesn’t take early, and EXPECTS to get the money a day or two later when the pay date is at weekend or BH.
Given rents are payable by SO and not DD, much like wages, it is up to the tenant to ensure payment happens on or BEFORE the due date. Therefore OP was unreasonable not to ensure payment happened and look ahead to realise there was a weekend.
At the same time, if the email really was harsh and nasty, rather than just businesslike and pointing out rent hadn’t been paid and reminding tenant that it must be paid on due date or before, this was probably unnecessary. I suspect it was simply businesslike and OP was overly sensitive to it. The fact she has now arranged another payment and might face double payment is a separate issue to the one of whether payment could be late. She should certainly expect the LL to refund one of the payments - no problem there.
The reason LL is likely to have sent a firm and businesslike email is so that this doesn’t happen again. Rent day will occur on BH or over weekend again. The LL wasn’t to make clear that the due date is the due date and that means before or on the date, and not later. Without the clear email, what’s happened could occur again.
As others say, one way to avoid this issue if SOs cannot be sent to happen sooner if a weekend is in place, is simply to arrange the payment date to be 3 or 4 days sooner, so it always arrives in time.
As an employee, I wouldn’t be pleased if my employer didn’t pay me on payday, and I had to wait 2 or even 3 days if there was a BH for my wages. There could be all kinds of things I needed to spend on that weekend and I was committed to. It is the same situation for this LL.