Your contract or other Ts and Cs of employment should define the pay date. Normally this would be one of:
- Last working day of the month
- Last calendar day of the month
In the former case, the payday is always a working day by definition. In the latter case, if the last calendar day is not a working day, the employer would normally pay you earlier to ensure the funds are cleared by the last calendar day of the month. This effectively makes the two definitions equivalent.
Assuming you are paid by direct deposit (direct transfer into your account) then this normally clears immediately, so there is no problem having the Direct Debits go out the next day. If you are paid by cheque or some other weird means, you would want some more buffer.
Speaking personally, I am paid on the last working day of the month and most of my Direct Debits are set to go out in the first one or two calendar days of the new month. Direct Debits work the opposite way in that if they fall on a weekend they will go out the next working day, not the previous. I have never once in 20+ years of working had an issue with this arrangement.