I thought about this for a little while, but couldn't think of a relatively easy way to get the weekends and outside normal business hours. Using an assignment rule for the weekend is easy to set up without having to modify the inbound email action, and you can add/remove conditions as fit to better match the inbound emails.
As for the time of day, I wrote a rather inelegant, simple script to check the incoming time of the email. If you remove or comment out the "current.priority = 3;" line in the inbound action, you can stick this snippet before the "current.insert();" and that should take care of it.
// Grab the hour value from the gs.nowDateTime() function
// returns as a value 0-23
var time = gs.nowDateTime().split(" ")[1];
var hour = time.split(":");
var finalHour = parseInt(hour[0],10);
// Set the number equivalent to hours of normal business hours (8 = 8 AM, 17 = 5 PM)
// Make sure to manually check instance time
var a = 8;
var b = 17;
if ( (a > finalHour) || (finalHour > b)){
//Outside of business hours
current.priority = 1;
}
else{
current.priority =3;
// Inside normal business hours
}
