Fix cron for last day of the month (#3831)

Co-authored-by: Jan Klopper <[email protected]>
Co-authored-by: stephanie0x00 <[email protected]>

rocky/reports/templates/partials/export_report_settings.html

@@ -21,6 +21,12 @@ <h2>{% translate "Report schedule" %}</h2>
                 {% include "partials/form/fieldset.html" with fields=report_schedule_form_recurrence_choice %}
 
                 {% if is_scheduled_report %}
+                    <p>
+                        {% blocktranslate trimmed %}
+                            Please choose a start date, time and recurrence for scheduling your report(s).
+                            If you select a date on the 28th-31st of the month, it will always be scheduled on the last day of the month.
+                        {% endblocktranslate %}
+                    </p>
                     <p>
                         {% blocktranslate trimmed %}
                             The date you select will be the reference date for the data set for your report.

rocky/rocky/locale/django.pot

@@ -3717,6 +3717,13 @@ msgid ""
 "single occasion, select the one-time option."
 msgstr ""
 
+#: reports/templates/partials/export_report_settings.html
+msgid ""
+"Please choose a start date, time and recurrence for scheduling your "
+"report(s). If you select a date on the 28th-31st of the month, it will "
+"always be scheduled on the last day of the month."
+msgstr ""
+
 #: reports/templates/partials/export_report_settings.html
 msgid ""
 "The date you select will be the reference date for the data set for your "

rocky/rocky/views/scheduler.py

@@ -276,8 +276,8 @@ def convert_recurrence_to_cron_expressions(self, recurrence: str, start_date_tim
                 # Recurres every year on the {day} of the {month} at the selected time
             }
 
-            if 28 <= day <= 31:
-                cron_expr["monthly"] = f"{minute} {hour} 28-31 * *"
+            if day >= 28:
+                cron_expr["monthly"] = f"{minute} {hour} L * *"
             else:
                 cron_expr["monthly"] = (
                     f"{minute} {hour} {day} * *"  # Recurres on the exact {day} of the month at the selected time