| Check(DateTime, Int32) | Check whether a date matches this special day. A usage is returned if the date matches the specialday. See also optimized version below, to use when date.Months and date.Day is precalculated. |
| Check(DateTime, Int32, Int32, Int32) | Check whether a date matches this special day. A usage is returned if the date matches the specialday. Optimized version, when the date.Month and date.Day is precalculated. |