This is not an Express, Ground or UPS exclusive issue. I see issues like this throughout the workforce.
IMO, it is incumbent upon the hourly to inform his/her mgt team
in a timely manner if they expect to be out of work for an extended period of time due to a personal or family tragedy.
The OP knew full well that he wasn't going to be able to work both Friday and Saturday-----would it have been that hard to pick up the phone on either Wednesday or Thursday to give his mgt team a heads up so that they could plan accordingly?
There is also the school of thought that says getting right back in to your regular routine helps you take your mind off of what just happened.
My son had a very close friend commit suicide during the Junior Prom. He had a fight with his date, walked to his grandfather's house, loaded his shot gun and pointed it at his stomach. My son was devastated, and rightfully so. My ex and I tried really hard to give him his space but after two weeks of "grieving" we both agreed that it was time for him to get back in to his routine so I called him early Sunday morning to tell him that I would be picking him up in time for his noon shift at McDonald's. He was

but on the ride home after his shift was over he thanked me for "forcing" him to start living his life again.