diff --git a/cara/apps/calculator/model_generator.py b/cara/apps/calculator/model_generator.py
index 6901bc62..d71aae50 100644
--- a/cara/apps/calculator/model_generator.py
+++ b/cara/apps/calculator/model_generator.py
@@ -174,14 +174,6 @@ class FormData:
 
         return models.SpecificInterval(tuple(present_intervals))
 
-    def minutes_to_string(self, minutes: int) -> str:
-        minute_string = str(minutes % 60)
-        minute_string = "0" * (2 - len(minute_string)) + minute_string
-        hour_string = str(minutes // 60)
-        hour_string = "0" * (2 - len(hour_string)) + hour_string
-
-        return f"{hour_string}:{minute_string}"
-
 
 def model_from_form(form: FormData, tmp_raw_form_data) -> models.Model:
     d = tmp_raw_form_data
diff --git a/cara/apps/calculator/report_generator.py b/cara/apps/calculator/report_generator.py
index 1bc46b60..1147897c 100644
--- a/cara/apps/calculator/report_generator.py
+++ b/cara/apps/calculator/report_generator.py
@@ -69,6 +69,15 @@ def plot(times, concentrations):
     return fig
 
 
+def minutes_to_string(minutes: int) -> str:
+    minute_string = str(minutes % 60)
+    minute_string = "0" * (2 - len(minute_string)) + minute_string
+    hour_string = str(minutes // 60)
+    hour_string = "0" * (2 - len(hour_string)) + hour_string
+
+    return f"{hour_string}:{minute_string}"
+
+
 def build_report(model: models.Model, form: FormData):
     now = datetime.now()
     time = now.strftime("%d/%m/%Y %H:%M:%S")