Time input validation in automation UI

[tokyotexture]

I wanted to add a 5 minute "for" requirement for a numeric state trigger in automations, and UI will let me save values that aren't valid and makes automation fail silently. Very non-intuitive for people not familiar with digging into HA logs.

I'm used to writing yaml in the format of
for:
hours: 1
minutes: 10
seconds: 5

so I assumed that writing "5 minutes" in the "For" field in the automation UI would work. I was able to save the automation without errors, and had to go to the logs to figure out what happened when it didn't trigger.

Logger: homeassistant.components.homeassistant.triggers.numeric_state
Source: components/homeassistant/triggers/numeric_state.py:177
Integration: Home Assistant Core Integration (documentation, issues)
First occurred: July 11, 2021, 6:40:09 PM (3 occurrences)
Last logged: 1:52:19 AM

Error rendering 'Send alert when freezer goes above 5 fahrenheit' for template: offset 5 minutes should be format 'HH:MM', 'HH:MM:SS' or 'HH:MM:SS.F'

I'm not sure if this should be an enhancement request or bug, but since it failed to parse without error, I'm inclined to say it's a bug. Obviously not a big deal to write "00:05", but UI is misleading/confusing. Why even have a text field if it's HH:MM:SS type input? I guess keeping it as a text field would be ok, assuming there's some validation, because I really thought I had a working automation when I saved it...