Change the severity of an Event on SL
Would it be possible to change or set the severity of a trap event if it occurs at a specific time.
e.g. Should it occur during business hours set/change it to a minor or should it occur after hours set/change it to another severity
SL1 does not facilitate the changing of severity for active event records nor directly changing event policy severity based on schedule.
Given some assumptions, you could hypothetically use Scheduled Run Book Automation, or an external scripting option, to make an API call against SL1 to update the Event Policy definition per your desired schedule. I'll note however that if there were questions that required historical triage this could add some confusion as to understanding the expected SL1 event severity during the given timeframe with frequent changes.
If these events are driving Automation and/or downstream ticket/incident creation I'd recommend whiteboarding the user experience or outcome you're seeking through changing the SL1 event severity and determining if those outcomes could be achieved through the logic invoked in those areas.