i think it depends on the award/contract your dh is hired under. my dh is eligible for one week paid, one week unpaid paternity leave. i think you have to have worked 12 months before you become eligible.

some workplaces you earn you accrue annual leave as you work and are able to access it as you earn it. other work places require you to work 12 months and then you get your 4 weeks leave on your anniversary date.

after 4 months, your dh should have accrued one weeks leave (if he gets 4 weeks a year). Hopefully he can find a nice HR person who can explain what his entitlements are.