diff --git a/AKModel/models.py b/AKModel/models.py
index 4c6d61880e6ad3267e76abe0fda61112d86f48b4..ef7da9a24fc42d00f1500fa73f0d8e212e0d14a0 100644
--- a/AKModel/models.py
+++ b/AKModel/models.py
@@ -1,5 +1,7 @@
+import decimal
 import itertools
 import json
+import math
 from dataclasses import dataclass
 from datetime import datetime, timedelta
 from typing import Iterable, Generator
@@ -382,6 +384,23 @@ class Event(models.Model):
                 constraints=category_constraints,
             )
 
+    def discretize_timeslots(self, *, slots_in_an_hour: float = 1.0) -> Iterable[TimeslotBlock]:
+        """"Choose discretization scheme.
+
+        Uses default_time_slots if the event has any DefaultSlot, otherwise uniform_time_slots.
+
+        :param slots_in_an_hour: The percentage of an hour covered by a single slot.
+            Determines the discretization granularity.
+        :yield: Block of optimizer timeslots as the discretization result.
+        :ytype: list of TimeslotBlock
+        """
+
+        if DefaultSlot.objects.filter(event=self).exists():
+            # discretize default slots if they exists
+            yield from merge_blocks(self.default_time_slots(slots_in_an_hour=slots_in_an_hour))
+        else:
+            yield from self.uniform_time_slots(slots_in_an_hour=slots_in_an_hour)
+
     def schedule_from_json(self, schedule: str) -> None:
         """Load AK schedule from a json string.
 
@@ -396,7 +415,7 @@ class Event(models.Model):
 
         timeslot_dict = {
             timeslot.idx: timeslot
-            for block in merge_blocks(self.default_time_slots(slots_in_an_hour=slots_in_an_hour))
+            for block in self.discretize_timeslots(slots_in_an_hour=slots_in_an_hour)
             for timeslot in block
         }
 
@@ -937,14 +956,17 @@ class AKSlot(models.Model):
         conflict_slots = AKSlot.objects.filter(ak__in=self.ak.conflicts.all())
         dependency_slots = AKSlot.objects.filter(ak__in=self.ak.prerequisites.all())
 
+        ceil_offet_eps = decimal.Decimal(1e-4)
+
         # self.slots_in_an_hour is set in AKJSONExportView
         data = {
             "id": str(self.pk),
-            "duration": round(self.duration * self.slots_in_an_hour),
+            "duration": math.ceil(self.duration * self.slots_in_an_hour - ceil_offet_eps),
             "properties": {
                 "conflicts": [str(conflict.pk) for conflict in conflict_slots.all()],
                 "dependencies": [str(dep.pk) for dep in dependency_slots.all()],
             },
+            "properties": {},
             "room_constraints": [constraint.name
                                  for constraint in self.ak.requirements.all()],
             "time_constraints": ["resolution"] if self.ak.reso else [],
@@ -954,6 +976,7 @@ class AKSlot(models.Model):
                                    for owner in self.ak.owners.all()]),
                 "description": self.ak.description,
                 "reso": self.ak.reso,
+                "duration_in_hours": float(self.duration),
                 },
             }
 
diff --git a/AKModel/views/ak.py b/AKModel/views/ak.py
index 90599a1ba26809c21c17495891ce4c527b827c26..1d60717b94a124731c542824d2f75110bcdb2389 100644
--- a/AKModel/views/ak.py
+++ b/AKModel/views/ak.py
@@ -9,7 +9,7 @@ from django.views.generic import ListView, DetailView
 from AKModel.availability.models import Availability
 from AKModel.metaviews.admin import AdminViewMixin, FilterByEventSlugMixin, EventSlugMixin, IntermediateAdminView, \
     IntermediateAdminActionView
-from AKModel.models import AKRequirement, AKSlot, DefaultSlot, Event, AKOrgaMessage, AK, Room, AKOwner, merge_blocks
+from AKModel.models import AKRequirement, AKSlot, Event, AKOrgaMessage, AK, Room, AKOwner
 
 
 class AKRequirementOverview(AdminViewMixin, FilterByEventSlugMixin, ListView):
@@ -114,11 +114,7 @@ class AKJSONExportView(AdminViewMixin, FilterByEventSlugMixin, ListView):
             if (values := AKSlot.objects.select_related().filter(ak__pk=ak_id, fixed=True)).exists()
         }
 
-        if DefaultSlot.objects.filter(event=self.event).exists():
-            # discretize default slots if they exists
-            blocks = merge_blocks(self.event.default_time_slots(slots_in_an_hour=SLOTS_IN_AN_HOUR))
-        else:
-            blocks = self.event.uniform_time_slots(slots_in_an_hour=SLOTS_IN_AN_HOUR)
+        blocks = self.event.discretize_timeslots(slots_in_an_hour=SLOTS_IN_AN_HOUR)
 
         for block in blocks:
             current_block = []