Tell him in advance that you want to sit down together, to have a conversation about the current routine, at a time when the kids are in bed. Tell him it’s very important.
Prep what you want to say in advance, to try to avoid getting lost in minor details. Rather than point out what you feel he’s doing wrong, explain what you want out of the routine, relationship and life itself and what in the current situation isn’t working for you (always working, staying out until 2). Tell him what is important to you. E.g, spending time together as a family. Spending time together as a couple. Splitting the family workload (e.g. childcare) equally. Explain WHY all of this is important to you and to the children.
Expect an argument, or bad reaction from him, after all, this current situation is him doing what he wants, when he wants. If he reacts negatively, or tells you, you’re being unreasonable, ask him why he feels that way and wait for him to answer.
If you’re able to stay calm, but firm about what you believe is going on and why you want and need it to change, you have a good chance of finding out what the future looks like. He’ll either take on board what you’re saying and take steps to right the wrongs, or he’ll dismiss your needs, which tells you there is a bigger problem.
He may react badly to start with (no one likes confrontation when they’re in the wrong), but if he then makes changes, you know he cares. If he shuts you down and carries on, you then should focus on what action you need to take, to improve the situation for yourself.