For a number of minor crimes several European countries use a system of day-fines where the fine you have to pay is a number of days decided after the crime and a per-day-value which is based on your income. The German law §40 StGB says the day-value should be 1/30 of your monthly net income. At what time is this net income assessed? Is it the net income at the time of the crime or the net income at the time of trial?
My motivation for this question was a recent ruling against German politician Kay-Uwe Ziegler where he was condemned to 60 days at 40 euros each. 40 euros day-fine corresponds to a monthly net income of only 1200 euros, this guy currently is a member of the German Bundestag so his current gross income is (at least) around 15000 euros per month, so these 40 euros seem extremely low.