Hi CT and welcome to the site!

Although it might appear that way sometimes, mindfulness doesn´t need to be some excruciating exercise.
Instead of deliberately maintaining mindfulness, maybe try to see what´s pulling you away from your current experience and form the intent to abandon it.
Just noting these distractions will slowly reduce the degree to which you´re "lost" in them.
Beware of being too harsh on yourself about falling back in your level of mindfulness: the best motivation to keep going is to have fun doing it.... playful, curious and with a good sense of humour for your own (and others) perceived shortcomings.

Martin

hello CT!

Do you have a regular sitting practice?
Even if its just 5-10 minutes morning and evening, committing to a regular sitting practice can do a great deal. Similarly, you can take out just a minute or two whenever you have a spare moment, to focus and be as mindful as you can for that short period. No need for formal sitting. These little things add up as they become more integrated into your life.

Also, simply having the intention to be mindful of everything that is happening, even if it isn't as deep as it might be. Noticing that it isn't deep is still noticing how it is. And through gradual noticing how it is as much as you can, perhaps it will deepen.

The transition between activities is also a big area where mindfulness can often be lost as we begin to think about the new activities. This is an area to be especially mindful of.

"Plowing through", in my experience, is an important aspect of training. But that is also just an attitude, and it needn't always be that way at all. Mindfulness can make your life easier. I think being reminded and committed to mindfulness and to wholeheartedly attempt to develop it as much as possible is the important thing. And you can do this without going on retreat, and without making it a chore, instead, to remind yourself to be mindful of each moment, whenever you remember to.

I am not too familiar with jhanas and how they work, or what it is exactly you are asking. But to make a simple distinction - there are states and stages. A Jhana state is something you'd train to reach during formal sitting concentration practice, not something you'd aim to experience through daily mindfulness (although you could). A jhana-stage might be something you'd have if you became very developed along the path and were able to live in that state during portions of your daily life. As for how long that would take, it depends completely upon how much effort you put into being mindful in each and every moment. I don't know what an average time could be like.

I hope this may be helpful to you (this is my first time giving advice so I may not be very good at this). More experienced members will surely give you much better advice though!

Hey CT, welcome to the DhO.

I'm a father, partner, home-owner and all 'round normal guy with a job so I can tell you quite confidently that it's possible to do what you're asking about. And more. Not being able to go on retreat isn't a big deal, it'd be useful and an amazing opportunity to practice solidly for the entire time but it's not required to get into jhana, or even to get stream entry and beyond. I know 'cause I've done it, as have loads of people in similar situations to yourself, some of whom also post on here and will hopefully offer some advice along the way.

How to increase mindfulness through the day? The first thing to remember is that every time you realize that you're not mindful, you actually are being mindful because you've just recognized the absence of mindfulness. Straight away, you're onto a winner here because that's a feedback system in itself; you're mindful and calmly attentive to what's happening right here and now, then you get distracted by something and go off on the thought train following the inner narrative as it plays out...then you realize you weren't being mindful and immediately you're back to being aware of what's happening right here and now!

Don't beat yourself up if you get distracted, it happens and it's done. No point in pursuing it around your mind, you won't catch it because it'll just vanish back to the emptiness it arose from, let it go and go back to being mindful, attentive to what's going on and enjoying this moment as it is.

To increase concentration, nothing beats a regular meditation practice done daily for as long as you're able to, even if it's only half an hour it's better than no practice at all. Off the cushion, there are lots of ways you can practice concentration creatively during daily life, the best foundation practice is simple breath counting in cycles from 1-10, returning to 1 if you loose count or get distracted. Stay with as much of the entire breath as you can, follow the whole of the inhale and the exhale, again if you get distracted it's no big deal, just go back to the breath again and you're back in business.

Another great concentration practice is "kasinas", which are various objects on which the attention can be fixed. A simple and easy to obtain example is a plain coloured bowl, prop it against a wall and focus on it as intently, actively and as engaged as possible. Again, if you wander off, just come back to it. Bring the attention back in the way you'd bring a puppy over it's water bowl, pick it up gently and place it with your object, whether that's the breath, a bowl, a candle, the whole body, the whole sensate field, whatever. It's that simple, really. It's a bit more subtle as you go along but the basics are the same and these examples are tried and tested.

How long it would take you to access jhana depends on a lot of things, but in general it's really not that difficult if you're willing to put in the work to get there. I'll post a few links for you which may be of use, hopefully the advice so far is of use to you but feel free to ask anything you like. Get a practice going, that's the most important thing, even if you need to get up half an hour early it's worth every second, even if it doesn't seem that way sometimes.

Best of luck and welcome on board.

The Hamilton Project
A site by some dharma buddies who also frequent this site, full of great practical advice and bullshit-free information about the nuts and bolts of practice.
My blog with an article on access concentration which may be of use to you.

I have recently discovered a dead simple and yet very effective technique taught by Shinzen Young called "Focus Out" which is to note "Touch, Sight, Sound" in real time, either out loud or just silently to oneself. Apparently it was taught to beginner Zen monks. I find that I can do it on the bus, walking down the street, etc., better than any other "continuity of practice" technique I have ever tried. Here is a link to the protocol. Good luck, and welcome to DhO!