I find a combination of online banking and Google Calendar to work well for this. For things that I want to deal with manually, I set up a recurring reminder in Google calendar. For other things which I want to pay automatically (fixed monthly amounts, for example), I have set up online banking to send an automated payment 7 days before it is due (this allows for the 5-day transfer time plus a 2-day buffer to avoid any late fees).
Google calendar is a great scheduled manager overall. And it's compatible with Outlook, so I can set up appointments within both of my calendar systems (work and personal) with a single entry.