The operation day abbreviations "vS" and "nS", are the DB Netz AG indicators for Sundays and public holidays (marked with "S"). Where:

• nS = train runs on business days after the days mentioned under S
• vS = train runs on business days before the days mentioned under S

(source: DB Ril 408.0101A03 state 13.12.2015)

Sundays before holidays or holidays before holidays (for example the 25.12) are not covered by the signs "vS" and "nS", since these are not business days. These days would have to be indicated as additional days when using these markings, if the train shall run on these days. Therefore, the vS / nS-rules are not necessarily suitable for mapping the pre-or subsequent day of "S" or "Sa + S", just like "Di-Sa [nS]" does not describe the following days after "Mo-Fr [S ]". The vS / nS regulations are therefore also considered obsolete and should no longer be used; better to avoid misunderstandings among all parties involved is the specific naming of the relevant date.

In this context, it should also be noted that the DB always uses a fixed date and only uses national holidays (currently New Year’s Day, Good Friday, Easter Monday, May 1, Ascension Day, Pentecost Monday, October 3, Christmas holidays (25.12./26.12.)). Holidays in FBS are freely definable. However, any differences in the holiday definition are converted into the FBS-TPN interface during the purchase order (recorded as additional or failure days). Thus, exactly the same days are ordered, which are also traffic days in FBS, only formulated differently if necessary.