LINQ return type for nested group query

I have the following query working in my code and now want to move into a separate class as a method that I call with List<Logrecord>, but having trouble determining what TYPE I need to return from the method.

recsByDate is a List<LogRecord> where records have Date, Time, EventType fields etc.

var vehicleGroupedByDate =  from daterecs in recsByDate
                                        where daterecs.Event == "Detection"
                                        orderby daterecs.Date
                                        group daterecs by daterecs.Date into vrecs
                                        from vrecs2 in
                                            (
                                               from daterecs in vrecs
                                               orderby daterecs.Time
                                               group daterecs by daterecs.Vehicle
                                            )
                                        group vrecs2 by vrecs.Key;