I think you will find the regulations (in Germany at least) say no more than 168 hours (which is 7 days) between weekly rest of two local nights, which can be as short as 36 hours.
Crewing has an incentive to have you start on earlies and finish on lates, but have you back ideally before 20.00. As most airlines are busier in summer working to the maximum then and being forced to take leave in winter is also pretty standard. Two crew overnight flights are regularly planned up to the maximum limit.
Of course lots of airlines have company agreements which are better than this, but the trend is downwards and even worse for cabin crew. We have hired a few recently from state carriers and some of the things I have heard are incredible.