When am I supposed to start applying for postdoc positions? (officially advertised positions with closing dates etc, not just informal enquiries) For example, I have found one being advertised now, closing date mid October - when would I be expected to start this (they don't say)? I will be submitting my thesis this time NEXT year.

Take advice from your supervisor, as practice in your area of research may be different from that in other fields. However postdocs advertised now will probably expect you to be able to start some time in the next few weeks or months - not in a years time.

Thanks - that makes sense. If they have funding for the project NOW (they mention this in the ad.), they'll want a postdoc to match that timescale.