Heya,
I can wear my most comfortable headphones nearly all day. I have to take them off when I get another beer, take a bathroom break, or take a phone call or simply get up to stretch my legs. Depends how much time I have to myself for it.
I find my Beyers (all DT series, so DT770, DT880, DT990) and my Denons (D5000) to be comfortable enough both from the pads, headband and weight to wear all day. My HE-500 is also now comfortable enough for all day as well after my cable was upgraded to a lighter build and a 3rd party headband pad added to increase padding. I can definitely do 8 hours on any of these. The combination of lighter clamp force, plenty of padding (soft pads, nothing firm) and headband padding with light cables makes them easy for me to forget I'm wearing nearly.
Very best,