Implement support of importing calendars from P6

src/ifcopenshell-python/ifcopenshell/api/sequence/edit_recurrence_pattern.py

@@ -1,6 +1,3 @@
-import ifcopenshell.util.date
-
-
 class Usecase:
     def __init__(self, file, **settings):
         self.file = file
@@ -10,17 +7,4 @@ class Usecase:
 
     def execute(self):
         for name, value in self.settings["attributes"].items():
-            if name == "TimePeriods" and value:
-                periods = []
-                for period in value:
-                    periods.append(
-                        self.file.create_entity(
-                            "IfcTimePeriod",
-                            **{
-                                "StartTime": ifcopenshell.util.date.datetime2ifc(period[0]),
-                                "EndTime": ifcopenshell.util.date.datetime2ifc(period[1]),
-                            },
-                        )
-                    )
-                value = periods
             setattr(self.settings["recurrence_pattern"], name, value)