Using 1970-01-01 in Date Item overwrites the Time-only flag of DateTime Triggers

[simonh1005]

trafficstars

Expected Behavior

When creating a DateTime Trigger for a rule whith time-only set to false, the rule should not trigger, if the DateTime Items contains a date in the past.

Current Behavior

If the rule contains "1970-01-01 00:00:00", the rule will trigger every 1am in the morning.

Possible Solution

I think, the problem is related to this line of code: https://github.com/openhab/openhab-core/blob/12f2314a2d1cbd3157bead4b6de9159bea37275d/bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/module/handler/DateTimeTriggerHandler.java#L180C21-L180C35

It assumes that the date 1970-01-01 means that the rule is time-only. In the edge-case of a user actually sending this date, this is unexpected behavior.

Steps to Reproduce (for Bugs)

A minimal rule to reproduce this looks like the following:

configuration: {}
triggers:
  - id: "1"
    configuration:
      timeOnly: false
      itemName: Alarmclock_Next_Schedule
      offset: 60
    type: timer.DateTimeTrigger
conditions: []
actions:
  - inputs: {}
    id: "2"
    configuration:
      type: application/javascript
      script: 'console.log("Debugging: Timestamp Rue has been triggered")'
    type: script.ScriptAction

Check your logs and you will see that the rule triggered at 1am in the morning.

Context

When trying to implement an alarmclock-rule that is triggered by a datetime trigger, I stumbled over a behavior, where the time-only flag is not working as expected when using a DateTime trigger. As I could not find a way to reset DateTime-Items to UNDEF, I use 1970-01-01 to express, that no date is selected.

Your Environment

• Version used: 4.3
• Environment name and version (e.g. Chrome 111, Java 17, Node.js 18.15, ...): Docker Image
• Operating System and version (desktop or mobile, Windows 11, Raspbian Bullseye, ...): Debian

[jimtng]

This was kind of by design. It's related to DateTimeType parsing a time-only string, the date part is set to 1970-01-01, and giving that to the datetime trigger means that you want a timeonly trigger. Perhaps it was done this way prior to the addition of timeOnly option, I haven't dug into that.

Need to think about whether there'd be any impact if we remove this. It would probably break some existing rules that relied on this specific behaviour.