although again it’s a very nice flow from @Peter_Kawa , perhaps here is a somewhat simpler solution.
Only issue is, it works with UTC (since Homey base time is always set to UTC/GMT).
new Date().setHours(18,0,0,0) - Date.now() < 5*60*1000;
This Condition Expression card will return true when the time is less then 5 minutes before 18u00utc.
