If you are paid by BACS they can hit anytime between now and the earliy ohurs if i rember correctly.. this seems to be the same for many different types of payment, as the electronic way this money is transfered depends on how your bank systems update overnight.. beleive it or not, i cannot access my 24 hour internet banking with lloyds tsb between midnight and 4am because there computer systems are doing the night run..
this link gives loads of info on different ways money are paid:
http://www.bizhelp24.com/small_busin...-money-2.shtml