If you want the confidence that comes from achieving what you set out to do each day, then it’s important to understand how long things are going to take
Over­optimism about what can be achieved within a certain time frame is a problem
So work on it
Make a practice of estimating the amount of time needed alongside items on your ‘things to do’ list, and learn by experience when tasks take a greater or lesser time than expected
Give attention also to fitting the task to the available time
There are some tasks that you can only set about if you have a significant amount of time available
There is no point in trying to gear up for such a task when you only have a short period available
So schedule the time you need for the longer tasks and put the short tasks into the spare moments in between