He was going to take 5 weeks for this next baby (#3) but alas I'm an army wife and he's now been told he'll be going overseas to relieve someone for 3 weeks in early July so it will depend when baby arrives (due 29th June) but then we'll take a week or so family holiday when he gets back. I'll be happy if he can at least be there for the birth and the few days following to look after DS and DD while I'm in hospital.
He missed DD's (#2) birth completely and didn't get to meet her until she was 7 weeks old and he had 10 days leave from his overseas deployment. With DS #1 I was lucky and had him for 4 weeks because DS was born in Jan just before we headed off interstate for a new posting.
Ideally I think for the first baby at least a couple of weeks would be nice as you both adjust to parenthood. Otherwise DH really has no idea what you are having to cope with each day and you could feel a little alone. With a C-section even longer would be better unless you have other family who can help. My sister recently had a C-section with her first baby and unfortunately her DH who is a chef had little time off and was working both a day and evening job. She was alone in a 2 storey townhouse with a new baby feeling overwhelmed and struggling with BF issues and still in alot of pain and not coping at all. Lucky we are currently living in the same city and I could go daily to help for a few hours but it still wasn't enough. She really needed someone there all day for moving things upstairs/downstairs, to help bring her baby for feeds and do nappy changes, to get her drinks and meals etc so she could rest instead of stress.
Also depends if your DH is the helpful type or is just going to sit around playing computer games on his 'holiday'! In that case lining up a mum/MIL or sister may be better