The current rule set has quite a bit of wriggle room in it - we are meant to have an average of at least 10 days off in each consecutive 4-week period, averaged over three such periods...In other words you are not guaranteed 10 days off every 4 weeks. It's also worthy of note that the rules go on to say that
"whenever practicable days off should be taken in the home environment."
I have seen comments elsewhere that some in short haul are not getting 10 days off at home per month, maybe someone more familiar with the short haul side of the operation will have more info.