I have the two variables:
1.sensor.time
2.input_datetime.stop_airco
I would like to use the "wait until node".
The node must wait until the time is stored in input_datetime.stop_airco.
I have no idea how to proceed from here.
Can someone help me?
Thanks in advance, Hans
Sensor time holds state "hh:mm" as a string, and is updated every minute. The comparison is usually done against a constant eg "10:08" but you can use an input_datetime if you use a JSONata expression for the 'value'.
The Wait until has to be against the 'state' property [of the named input_datetime entity].
The comparator can be ">=" although 'is' works ['is' matches the exact time, but '>=' will match historic times that have now passed]
The value option must be set to J: expression for JSONata, and you need
$entities('input_datetime.help_stop_ac_time').state~>$substring(0,5)
as the expression.
$entities('name') will return the entity state object of any named entity, so here the input_datetime holding the test-time, and .state. gets the state.
Since input_datetimes, setup to "time", hold the time as "hh:mm:ss" as a string, we need to truncate this to just the "hh:mm" part, so the ~> is a function chaining operation, and $substring(0,5) uses the context to start at character 0 for length 5.
Comparing strings is always tricky, but as long as 'sensor.time' returns the 24 hour clock and likewise for the input_datetime, it will work.
The Wait Until node will "wake up" every time the subject entity property changes, in this case the sensor.time state value, every minute. The comparison value, in this case a JSONata expression, will be re-evaluated at this point. If the node is triggered at, say 10:00 with an input_datetime value of 11:00, and then the input_datetime is later changed to say 10:20, if the time is before 10:20 the node will trigger at 10:20, but if the time is after 10:20 but before 11:00, the node will trigger at the next minute update of sensor.time, but only if the comparision is ">=". If the comparison is "is" and the input_datetime time has already passed, the node will not trigger until tomorrow, so I believe it is worth using ">=" even though this can be problematic with string comparisons.
Edit:
If setting a 'turn off' during the evening for the following morning - time 22:15 and input_datetime (time) of 07:30, then is is required, so better to stick with is really !
Problem solved.
A very good and clear explanation.
Thank you.
Greetings Hans
