Kernrechtsfrage
Whether retroactive maintenance could be calculated using the husband's later, improved financial situation for an earlier period
Extrahierter Entscheid
No. Maintenance for a past period must be based on the parties' actual financial situation during that period; materially changed circumstances require separate periods and differentiated calculation.
Extrahierte Begründung
The husband's expenses changed substantially only from 2004 onward, when he obtained a free right of habitation and related benefits. Using those later circumstances for the earlier retroactive period contradicted the effective situation and was arbitrary.