Okay here’s my experience: My GF was going to be delivered on a Thursday that I absolutely could not take off work, and there is no way I can pick up my Glowforge from UPS given my tiny car and my physical injuries, so I went and signed up for UPS My Choice as the ship notification e-mail suggested.
It was not free. Sign up for the My Choice thing was free, but it cost me $5 per package (so $10 total, since I already got the PG materials) to delay delivery until the next Monday. When I went to change the delivery date it gave me a calendar with a bunch of choices, and if I remember correctly it went out at least a week, if not more. They may charge more for a longer hold.
I actually wanted to change the delivery to Friday (just the next day) but they didn’t give me that as an option.
Once I changed my delivery date they gave me a new delivery window of 9AM to 1PM on the day indicated. I could pay additional money to narrow it down to a 2 hour window ($8 per package) but I decided not to. The packages showed up at the new time as expected.
There’s a premium tier My Choice account which costs $20 or something and maybe that offers more features? I’m not sure because I didn’t care enough to investigate.
One important note is that they can only delay delivery if you request it within a certain time window, probably before they pack the trucks early morning or something. I had a day to do that. Some people on the forums said they got the notification of tracking number right before getting the thing delivered. I would suggest signing up for the free My Choice account ASAP because then UPS will send you a message whenever any package going to your address enters their system so you don’t miss that window.