Only Headway Interval is curretly part of the model
but to properly use frequency trip based information in route planners or start time and end time should be supported or start time and number of occurences should be supported
because you define 3 options for HeadwayInterval (max min or scheduled)
Hadway Interval
I recommend to support start time and end time or have a clear linkage with the service calendar
In the timetable model https://purl.eu/doc/applicationprofile/netex-belgium/timetables-ap/working-draft/2022-04-21 for the following Journey Frequency
Only Headway Interval is curretly part of the model but to properly use frequency trip based information in route planners or start time and end time should be supported or start time and number of occurences should be supported because you define 3 options for HeadwayInterval (max min or scheduled) Hadway Interval I recommend to support start time and end time or have a clear linkage with the service calendar