Close, but not a full 2 days for me. I have gotten accustomed to charge my phone nightly even though I get about 60% charge left at the end of a day. If I do forget, charging it during my 30 minute commute gets my phone through the second day with no problems.
Every person is going to be different. We all run different apps or have different uses for a phone. The Z3 has a couple of battery saving modes which I don't see why you could not get through 2 days.
I came from an S5 and with my needs of a phone, the Z3 outperforms it when it comes to battery life.