You've quoted your time that it will take certain time to produce a piece of software. When you have started the project, is it better to go hard at the beginning and cruise later? or to try to maintain a consistent effort throughout the project?
Commitment level to the project?
project management;development process;time management
Take the hard parts first.  They are the uncertain parts, so getting rid of those makes it easier to determine how much work you need to do yet.