Add ecobee indefinite away preset, remove unusable/broken presets (#108636)

* Add ecobee indefinite away preset, remove unusable/broken presets

* Revert cleanup of presets which no longer work

homeassistant/components/ecobee/util.py

@@ -1,6 +1,6 @@
 """Validation utility functions for ecobee services."""
 
-from datetime import datetime
+from datetime import date, datetime, timedelta
 
 import voluptuous as vol
 
@@ -23,3 +23,13 @@ def ecobee_time(time_string):
             "Time does not match ecobee 24-hour time format HH:MM:SS"
         ) from err
     return time_string
+
+
+def is_indefinite_hold(start_date_string: str, end_date_string: str) -> bool:
+    """Determine if the given start and end dates from the ecobee API represent an indefinite hold.
+
+    This is not documented in the API, so a rough heuristic is used where a hold over 1 year is considered indefinite.
+    """
+    return date.fromisoformat(end_date_string) - date.fromisoformat(
+        start_date_string
+    ) > timedelta(days=365)