Yes - your employment contract should state the day(s) on which you should receive your salary and the dates for which the salary applies i.e. "your salary will be £36,000 per annum payable per calendar month and will be paid on the last Friday of the month by direct credit transfer".
Any deviation from that (outside mutually agreed amendments) is a breach of contract. But, if your employer has no money, whaddya gonna do?
Anyone who is self-employed/freelance is in an even weaker position unfortunately.
Cheers
Whirls