End of 15 hour work day

I spend about 13 hours a day working.  It is not something that my boss demanded of me.  I just put in as much as I can to solve things that are coming my way, and when I count all the hours that I spend on average, it comes out to be about 13 hours a day.  That does not include chores like washing up, eating and commuting.  It's 13 hours in front of my laptop doing one thing or another.  That means I work about 15 hours each day, Monday thru Friday.

When I put in 15 hours day in and day out, I started to notice that I lose my daily rhythm.  Each day bleeds into another.  Back-to-back 5 hour sleep cycle starts to wear on me as mid week rolls in, and by Friday I become a walking zombie kept awake by the power of black Peet's coffee of the day.  There is no unplugging, hence there is no transition.

I am finally acknowledging that it may be causing more harm than doing good.  Being always on is not the answer to increase the productivity.  I have to take a longer term perspective, and pace myself.  The race won't be determined by who gets to cram in more working hours a week.  Instead it will be about how fast I can evolve the product, and whether I will keep going when product-market fit starts to find its sweet spot.  As they say, it's a marathon, not a 100m dash. 

Simply allocating more time to get more done cannot be the sustainable strategy.  I first have to specify the beginning and end of each day, then put the rest of things within the available time.

It's going to be difficult to do because I'm used to adding more time to get things done.  But it's something that I am willing to try.

Let me see how successful I can be.

Product Management: Do important things first

When my day is driven by meetings with people in 30 minute increments, it is difficult to see where my focus is.  That makes sense.  When I'm reacting to those meeting requests, I am not focusing on things that will make a difference to the product.  If you believe in managing your resource like I do, the most important resource is time.

When I was working as a developer, I did not have this problem at all.  I would get a project to work on, I set my schedule to tackle one problem on my proposed timeline.  My manager would then take that schedule, negotiate it with me, and he would project manage to make sure that I was on track or behind.  All I needed to do was to think about how to solve the problem at hand.  One big problem and smaller problems that would lead to a grand solution.  When I sat down to do some coding, sales guys didn't ping me to ask about the product roadmap.  Business development didn't pull me in to the partnership deal that he was working on.  Life was simple.

Product Management: allocate your time

I remember feeling that having 8 hr day was plenty of time to write useful piece of code.  When I could concentrate on coding without interruption, I often was surprised how much I was able to get done in a day. When I was writing code full time, I had to master how to write and test incrementally.  Writing small easy to understand code was the skill that I practiced every day.

It's been just about 2 years that I've been wearing product manager hat.  What would be the number one skill that I need to practice and get better at?