I wounder how
OpenCPN (or the oeSENC-plugin) handle
ENC features that are encoded with the attributes DATSTA, DATEND, PERSTA, PEREND?
PERSTA and PEREND is used to encode between which dates the feature is valid. This is used for eg seasonal bouys.
DATSTA and DATEND is used to encode the first or last day a feature is valid. This is eg used when information is published in the chart in advance. Like when new traffic separation schemes is to be implemented.